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Damienl
05-22-2014, 06:43 PM
First off, sorry if I posted this in the wrong place - I didn't know whether to post it here or oil painting.

I've searched the site for info on this, and learned a few things but nothing that directly answered my questions on the opacity of burnt umbers.

In my googling of the forum, I came across lots of talk of the pigments, lists of the pigment loads of burnt umbers from most of the major manufacturers, and the key things I heard said multiple times are:


Real burnt umber contains manganese.
Real burnt umber is PBr7.


Now lets look at a weird example: Rembrandt uses PBk11 & PR101 - but strangely, it's baby company Van Gogh uses PBr7.
Both are listed as semi transparent.

Ok, cool, that's weird and I don't understand why the lower end would use the "real" pigment and the higher end would use a mixture.

But what's even weirder and I understand even less, is the difference between Winton and W&N's Artist burnt umbers.

Both use PBr7. The color index name and number is identical in both tubes. Winton is labelled fully opaque, Artist is labelled fully transparent.

The chemical description from the Winton color chart is as follows:


Calcined natural iron oxide


Vs. the Artist color chart:


Calcined natural earth


Now, besides this being annoyingly baffling... I was under the impression that while the fancier colours (cadmiums, cobalt whatsits, etc) were hugely different between student and artist grade, that the oldest, most basic paints of all time - the umbers, siennas, etc, weren't that different from student to artist level.

Can anyone make sense of the opacity and what-the-hell-is-going-on-with-the-pigments question?

WFMartin
05-22-2014, 08:49 PM
In my experience Umbers (both Burnt and Raw) have got to be the most variable and different colors of paint that exist. Between brands some of the Umbers are quite different, and the differences between the "Raw" and "Burnt" versions of Umbers within the same brand seem to be very elusive.

I just buy umbers by their color, opacity, and the way I want them to handle for the specific purposes to which I put them. I don't believe I've ever actually read the pigment ingredients indicated on the labels of most umbers, and not nearly as often as I read the pigment ID's on other colors.

For example, at present, I'm using up an old tube of (of all things) Shiva Raw Umber that I "inherited" from someone. There is no pigment ID on the label. What is truly strange is that I'm actually beginning to love that paint, as it fills a "gap" in the "near-neutrals" that I needed to fill, and I know when its gone, I will probably need to find something to replace it. It's grainy, and it smells "cheap", but it works like a charm, actually.:lol: Well, go figure!:smug: I'll probably be hunting for quite some time.

So, as I said, I'd purchase Umbers by merely trying them out, and making a decision what works the best for your operation. Oh......and, it's best to make your selection from paint brands that are going to be around for some time. Except for handling differences, I select most paints for their specific colors, based upon their convenience to me in using them in mixes.

I consider myself to be a bit of a "color theorist", and most color theorists are mostly interested in the color of a paint, regardless of the way it may have become such a color. Handling, and oil binder are other considerations, of course.

Gamblin offers some of the whackiest colors I've ever seen, such as Gold Ochre, Asphaltum, and Brown Pink. I believe each of these colors is a mix of at least 2, if not 3 separate pigments, but these colors are very useful for specific requirements, and they are convenient to use.

Umbers vary all over the place, by brand, as well as by artist quality, and student grade. I'd just recommend you try a few, and pick the one that works best for your operation.

Mythrill
05-22-2014, 09:56 PM
First off, sorry if I posted this in the wrong place - I didn't know whether to post it here or oil painting.

I've searched the site for info on this, and learned a few things but nothing that directly answered my questions on the opacity of burnt umbers.

In my googling of the forum, I came across lots of talk of the pigments, lists of the pigment loads of burnt umbers from most of the major manufacturers, and the key things I heard said multiple times are:
Real burnt umber contains manganese.
Real burnt umber is PBr7.Now lets look at a weird example: Rembrandt uses PBk11 & PR101 - but strangely, it's baby company Van Gogh uses PBr7.
Both are listed as semi transparent.

Ok, cool, that's weird and I don't understand why the lower end would use the "real" pigment and the higher end would use a mixture.

But what's even weirder and I understand even less, is the difference between Winton and W&N's Artist burnt umbers.

Both use PBr7. The color index name and number is identical in both tubes. Winton is labelled fully opaque, Artist is labelled fully transparent.

The chemical description from the Winton color chart is as follows:
Calcined natural iron oxideVs. the Artist color chart:
Calcined natural earthNow, besides this being annoyingly baffling... I was under the impression that while the fancier colours (cadmiums, cobalt whatsits, etc) were hugely different between student and artist grade, that the oldest, most basic paints of all time - the umbers, siennas, etc, weren't that different from student to artist level.

Can anyone make sense of the opacity and what-the-hell-is-going-on-with-the-pigments question?
Yes. If you have garden soil that is rich in iron and has at least some oxide of manganese, you can make your own raw umber.

You're probably saying to yourself now: "Wha–? That has nothing to do with what I asked!"

The thing is, by making your own umber, you'll notice that even patches of soil from your own garden may have a very different composition. I got some soil to make Raw Umber from my house, and it was noticeably darker than the soil a neighbor gave me, which was much yellower and lighter. That has probably to do with more iron and less manganese oxide in its composition, which gives natural Raw Umber the "golden poo" hue many artists hate.

The reason some brands use synthetic pigments to make a "Raw Umber" is simply because it's easier to control its handling characteristics. In the case of Rembrandt Oils, they're using Mars Black (PBk 11,) which has a blue/green bias, and making it slightly warmer by (most likely) using Transparent Red Iron Oxide (PR 101.) Mars Black is very opaque, so the transparency of this version of Red Iron Oxide makes your paint semi-transparent.

Grinding differences and filtering (if you only use natural earth) will also affect tinting strength and opacity. If you use an aqueous suspension and boil earth for a while at 100ΊC, the finer particles will crumble, and this will give you a very small quantity of very fine particles. If you get enough of these, there's a very high chance that your paint will be more opaque and finer; on the other hand, if you're impatient and just filter organic matter, quartz and silica particles (i.e, sand) might go into the mix, which will make your pigment gritter and more transparent.

There's another reason why companies will mix other pigments into umbers: the version I used with acrylics, for instance, was very lifeless in masstone. If you saw the color, you'd be instantly put off, so it's not "markeatable." What was surprsing, though, was that, once it was dry, the light shone very beautifully, and it was much more transparent in acrylics, giving me cleaner mixes than the Winsor & Newton Finity Raw Umber, which was brighter in masstone! I could even mix it with PY3 ("Lemon Yellow",) and I would get a beautiful, green-gold-like hue!

On a side note, Winsor & Newton's Finity Raw Umber was unevenly dispersed, so it behaved more transparently. When I dispersed it to behave evenly, it suddenly went opaque! I wonder if the uneven dispersion was on purpose.

Unfortunately, true Raw Umber is a very fast drier and needs stabilizers to last long. I used the wrong humectants too, so I lost my batch after around 6 months. This is yet another reason might want make the hue from synthetic iron oxides. Since they don't have oxides of manganese, they're easier to stabilize.

By the way, there are also many ways for manufacturers to sell "Raw Umber" while still keeping it "Raw." If they got a yellowish Raw Umber, all they need to do is buy some oxide of manganese and and add it to their earth, and... voilα! "Cyprus" Raw Umber. Add 10-20% to your earth, and it will have the greenish cast envied by so many artists.

If you have the time to make your own Raw Umber, by all means do so. As I said, compared to modern pigments, it will probably be very dull in masstone and very weak tinting strength; however, it lays very beautifully, which is great for glazes. You can gracefully glaze it over a passage of Quinacridone Rose lightened with Titanium White (PV19-gamma + PW 6,) and it will still look like a graceful shadow. This is something I consider unthinkable to do with the commercial brands I have (it would look dirty instead.)

Since I don't have the patience to filter out all that pigment though (and I can't afford to pay for all that oven gas) I bought Golden's version. They list their pigment as opaque, but hopefully, it will glaze well when mixed with acrylic gel.

Mythrill
05-22-2014, 10:08 PM
Sorry, I forgot to say something. Let me add to the story:

I mentioned Raw Umber, but you asked about Burnt Umber. It turns out that real Burnt Umber is exactly what the name says – roasted Raw Umber.

I posted a thread in this very forum about my paintmaking. It has both of them:

http://www.wetcanvas.com/forums/showthread.php?t=1328765

Since I don't have an oven, in my case I got some soy oil and fried the "Raw" Umber (and then washed out the traces of soy oil.) The result is just as described historically: an earth color of redder hue.

I'd like to amend something, though: in the original acrylic recipe, I used honey as a humectant. Don't do that! If you choose acrylics, use a regular Acrylic Retarder to keep the paint stable, and keep a nice balance between pigment and paint film (gel) so that the pigment won't separate and dry. Also, instead of water, add a mix of 50% water / 50% alcohol to make an aqueous dispersion in acrylics, and use ammonia (the one you buy on a drugstore) to keep acrylic paint alkaline.

Damienl
05-24-2014, 12:36 PM
Mythrill, thanks for the info!
That thread of yours about umbers is fascinating - Now I know what I'm going to be doing for the next week. Haha
Last night I did a few tests, and contacted Windsor Newton.
They said the different names applied to the PBr7 in each tube are the same thing, and a different product manager may have just named them differently.
The person who replied also said that she personally tested them both, and the opacity is the same, so there's a typo - on every tube of W&N Burnt Umber. At least in Canada. :lol:

Of course being a huge nerd when it comes to this stuff I went out and bought some W&N umbers, even though I can't afford to (my poor wallet has been through so much getting paint supplies already :eek: ), and did some testing.

This probably won't surprise any experienced painter, but it helped me out. There is very little difference I found between all of these paints except the consistency and smoothness/creaminess of the paint. (As a side note, I'm a hairdresser and therefor spend a lot of time mixing colour, and the same thing is very noticeable in hair colour - tubes of cheaper colour, particularly italian colour, are very dry and you use a whole tube to get something done, whereas the more expensive brands which are often german, are buttery and a tiny bit covers a huge amount)

Each colour is squirted out, spread with a pallet knife on top, and lightly brushed on the bottom.
Left to right:


Pebeo XL Raw Sienna, $1.50.
W&N Raw Sienna, $10.99
Winton Raw Umber, $5.99
W&N Raw Umber, $10.99
Van Gogh Burnt Umber, $14.99.
W&N Burnt Umber, $10.99.


http://www.wetcanvas.com/Community/images/24-May-2014/1791740-umbers.jpg

And I grabbed another test board I had for testing out various mediums and mixes to get some idea of transparency. The numbers correspond to the list above.

http://www.wetcanvas.com/Community/images/24-May-2014/1791740-umbers2.jpg

Obviously the Pebeo tube I got for $1.50 doesn't hold up to W&N, but to my surprise the difference between Winton and W&N was the biggest. The colours above are all accurate (on my monitor at least), but the Winton is a bit more opaque and a much rougher grind than the W&N.

And then the Van Gogh and W&N were nearly indistinguishable. In colour and handling. I have to tip my hat to Van Gogh here, I wasn't expecting that from what I hear "around the watercooler"! Just goes to show that testing things yourself is the best way to learn I guess!

Mythrill
05-24-2014, 05:51 PM
Hi, Damien!

Did they really say that all their tubes of PBr7 have the same material? I'm quite shocked. That's far from the truth!

The thing is, all tubes of PBr7 have Iron Oxides in a way or another. The thing is, the types and amounts of impurities are what change the hue and behavior and give us what we call "Raw Sienna", or "Raw Umber," and so on. Calcinating them or not will also alter the components and hue.

In this context, those impurities are highly desirable.

Maybe them mean to say their base pigment is PBr7 (some sort of natural iron oxide) and they alter the hue accordingly with something else depending on the hue they want?

Regarding the brands you listed: Van Gogh paint is from Royal Talens, (originally Dutch,) Pebeo is French, and Winsor & Newton is English.

I really like the comparison you made, and I'd like to comment a little on them.

1. Pebeo XL Raw Sienna (Student-grade:) Pebeo is always changing the ingredients of their XL line. If you got their current Raw Sienna, their tube is probably a mix of PBr7 + PY42 + PY74.

The mix in itself is pretty sound, but the addition of an Azo Yellow (PY 74) makes me frown. The reason is that Azo Yellows can vary greatly in quality, and considering the earth pigments are far more stable, the azo component of the paint may fade and change dramatically of hue, giving your paint an unpleasant cast you originally didn't intend it to have.

This mix is in-line with the proposition of this line, though: they want to offer artists the brightest colors, and adding PY74 to the mix makes the tube a bit cheaper, too, which is why you see it sold at this price. Not necessarily a bad paint, but I wouldn't want to buy an earth color mixed with an Azo. The chroma is also a bit too high (unnaturally orange-y.)

2. Winsor & Newton Artists' Raw Sienna (Artist Grade): that's actually Natural Yellow Ochre (PY 43) mixed to Synthetic Yellow Iron Oxide, Transparent (PY 42.) The result is a beautiful, even color that's historically close to a historical high-quality Raw Sienna. True Raw Sienna is PBr7 as well, but probably with a very, very low content of manganese oxides. True Raw Sienna is still very bright, but it still has a brownish cast. Consider it a very yellow shade of Raw Umber.

3. Winton Raw Umber (Student Grade:) this one has the addition of Bone Black (PBk9) to deepen the hue, giving it the "greenish" cast artists seem to love. The problem is that, by adding Black, the mixes with this Raw Umber are much less chromatic than just the real thing.

Try to mix this one with yellow. I suppose you should get a muted green, but can you post the result here just in case?

4. Winsor & Newton Raw Umber (Artist Grade:) they claim to have just PBr7 there, but basing myself on their Finity Acrylics (Artist Grade,) I suppose it too has a touch of Black to deepen the hue – just not as much as their "Winton" line, though.

5. Van Gogh Burnt Umber (Student Grade [?]) & 6. Winsor & Newton Burnt Umber (Arist Grade) (PBr7:) I'm almost as surprised as you that these two have the same quality, as Van Gogh is listed by Old Holland as a Student (!) Grade.

I have two Van Gogh tubes in oil: Raw Umber (PBr7) and Cobalt Blue (PB28.) Both Van Gogh's tubes seem to "melt" in the brush, and are really pleasant to work with.

It's really odd, though, that both Burnt Umbers in these brands have exactly the same handling. And they're really uniform, too. If you make the pigment yourself, you'll see that even if you only get its finest particles, the granulation is a bit visible and slightly uneven. That suggests they're mixing unlisted pigments to improve the color matching and evenness of paint.

It's also worth mentioning that, comparing Burnt and Raw Umber of both brands, the "leap" of shade is quite big. They went from too greenish to very reddish. Maybe they got a really good oven and are burning the pigment at higher temperatures than I did (compared to frying in a pan,) but given the green cast, the result in masstone would probably be a bit grayer. Or maybe they're burning a yellower shade of Raw Umber?

A reasonably cheap alternative to make the pigments more attractive would be to add small amounts of synthetic iron oxides (PR 101, PY42, PBk11) burned at different temperatures to improve the handling. If done carefully, it also doesn't change the masstonehue of the paint substantially, as you aren't changing the composition of the paint very much either (as they're all iron oxides, in essence.)

One reason I suspect they do this is because it has already been reported on this very forum that even the "natural" Yellow Ochres being sold (PY 43) are 1/3 natural, and the rest is mixed with synthetic iron oxides to keep color consistency.

Another reason of my suspicion is that even the colors that have low tinting strength (like Van Gogh's Raw Umber) are actually much stronger than the Umbers I made at home. When I dispersed them correctly, they were almost as transparent as Quinacridones – just not as clean and bright as Quinacridones are. True Umbers (Raw, Burnt, etc) would have not much lower chroma in masstone, but would also much lower tinting strength, which isn't much successful commercially. The only way to do a home-made Umber that has a strong tinting strength is to make it a bit coarse, which might give you handling properties you might not like.

And, as I already said, it's hard enough to obtain the same hue from Umbers even if you get them from the same "batch" (the same garden, for instance.) How come manufacturers can keep the color match not only through thousands of batches, but even keep the same hue among different manufacturers?

Damienl
05-24-2014, 08:11 PM
Mythrill, that's fascinating. I have noticed PR101, PY42, and PBk11 in a lot of tubes I was looking at comparing umbers and siennas and earth tones.

I'm trying out some home paint-making, inspired by your thread - I just dug a hole in the ground (4' deep!) and took some earth and clay from three different levels. Each had a different look to it, so I thought I'd try them all out and see what happens with each. The middle had a slight yellowish tinge to it, and the bottom stuff was a cool (green undertone but only slightly noticeable) grey.

Excited to see what turns up when I get these things ground up! Now I just need a mortar and pestle, and a muller... lol

Mythrill
05-24-2014, 09:25 PM
Mythrill, that's fascinating. I have noticed PR101, PY42, and PBk11 in a lot of tubes I was looking at comparing umbers and siennas and earth tones.

I'm trying out some home paint-making, inspired by your thread - I just dug a hole in the ground (4' deep!) and took some earth and clay from three different levels. Each had a different look to it, so I thought I'd try them all out and see what happens with each. The middle had a slight yellowish tinge to it, and the bottom stuff was a cool (green undertone but only slightly noticeable) grey.

Excited to see what turns up when I get these things ground up! Now I just need a mortar and pestle, and a muller... lol

There's a filtration process that won't make you need a grinder. It doesn't change the composition of your umber either, since the color starts to change at 300°C, and you'll get artist-grade pigment. Here's how you do it.

Boil the ground on a pan you won't use at 100°C (boiling water temperature.) for around 10-30 minutes, as if you were cooking soup. Then, filter it using a strainer (or very fine rags, like cotton.) Make sure to filter out all the big particles so that your solution should like a "coffee" drink.

This boiling process will not ensure you'll get the finest particles, but will also filter out all the organic particles of your umber.

After that, let it sit for around 24 hours. The more you let it sit, the more the finer particles will break down, and will give you "finer" umber (i.e, the "good" stuff.)

After that, pour the water to another recipient. The particles will be so fine that agitating the water will make them mix into it again, so don't agitate the recipient too much.

The important part: the particles will be so fine that they could go into your longs, so keep them "stuck" by an aqueous dispersion, i.e: always make your new pigment slightly wet.


These instructions are oil-specific.

If all went right, you should near nothing but the sound of the muller when mulling your pigment (almost like if you were mulling a lake.) After a while, you should get a syrup consistency. While it will dry perfectly, the end result won't be suitable for impastos. If you want a thick consistency, follow the instructions below.

Making your paint have "tube-like" consistency (WARNING: WEAR A RESPIRATOR!)

If you want to add a buttery consistency to your paint, get some beeswax and mix it with only a little of mineral spirits to the pan.

Now, wear your respirator. You should mix your beeswax and mineral spirits into the oven for 2-3 minutes at low temperature. Make sure nothing has spread into the oven so nothing will catch on fire.

After that, you should notice the mix won't go into its natural, solid state. You should mix that into your pigment, and you're done.

Storing
If you want to store your paint (you probably will, because it takes too much work to do it this way,) get an empty tube (like the one sold in drugstores,) and then seal the paint.

With acrylics, assuming you have got the ratio of humectants, binders and pigments right, you can keep the contents in a jar. But with oils, that's just impossible (I tried.)

You can also keep the aqueous suspension stored and mull your pigment whenever you start working with oils. You'll have a little more extra work every session, though.

Mythrill
05-24-2014, 09:32 PM
The downside of the filtering method below is that it's very time-consuming, and you'll get very little pigment per batch of soil.

Also, there's one thing to consider independent of the paint binder (oils, acrylics, egg tempera:)

DO NOT ADD SICCATIVES TO ANY UMBER YOU ARE GOING TO STORE (E.G, COBALT DRIERS.) IRON OXIDES DRY PRETTY FAST ON THEIR OWN, AND THE NATURAL OXIDES OF MANGANESE PRESENT IN UMBERS SPEED UP THE PROCESS FURTHER.

ADDING SICCATIVES TO ANY UMBER YOU'LL STORE WILL MAKE IT DRY ON THE TUBE, RUINING YOUR PAINT.

IF ANYTHING, CONSIDER ADDING OIL-SPECIFIC HUMECTANTS TO PREVENT YOUR PAINT FROM DRYING IN THE TUBE.

Damienl
05-25-2014, 03:14 AM
That is some awesome info! Thanks a lot! I can't wait to try it out tomorrow. After I go to the thrift store to get a frying pan or two. :lol:


The important part: the particles will be so fine that they could go into your longs, so keep them "stuck" by an aqueous dispersion, i.e: always make your new pigment slightly wet.


I have a question about this - how do you transition from the filtering process (with the pigment in water) to the pigment in oil for creating oil paint, without drying the pigment completely to powder?

If you were mulling it, and added some oil, kept mulling, added a bit more oil, would the water eventually evaporate out of the mix?

Mythrill
05-25-2014, 09:35 AM
That is some awesome info! Thanks a lot! I can't wait to try it out tomorrow. After I go to the thrift store to get a frying pan or two. :lol:



I have a question about this - how do you transition from the filtering process (with the pigment in water) to the pigment in oil for creating oil paint, without drying the pigment completely to powder?

If you were mulling it, and added some oil, kept mulling, added a bit more oil, would the water eventually evaporate out of the mix?

Oh, don't worry. Just add linseed oil to the aqueous dispersion as you normally would The pigment in the aqueous dispersion will resist binding to the linseed oil initially. After a while, tough, it will separate from the water and bind to linseed.

Just make sure to keep the water in the aqueous dispersion to a minimum (only to keep the pigment slightly wet.) :)

Damienl
05-27-2014, 06:42 AM
Well my first attempts are....fledgling...But at least it resembles paint!
It still needs to be ground finer - I don't have a muller, and using a glass with the flattest bottom I can find isn't exactly doing the job, so I think I'm going to have to get some sandpaper and make myself a muller. (Nobody around here sells them)

This is after grinding down in a mortar and pestle, filtering, grinding some more, filtering (through a tight metal strainer), boiling, letting sit, removing the water from the mix after it separated and filtering that mix through an old t-shirt, adding oil and "mulling" with my glass and/or big palette knife.

It took a surprising amount of oil - I added quite a bit, and it didn't bind, kept going and added a bit more and it started clumping, added a bit more and kept going and it finally started to turn into a paste.

It's still a little gritty, and it feels more like a suspension than a cream... AND I think there was still some water in there... but for a first try I think it's not bad.
I circled it next to the W&N umber.

http://www.wetcanvas.com/Community/images/27-May-2014/1791740-dsg.jpg

Mythrill
05-27-2014, 02:09 PM
Well my first attempts are....fledgling...But at least it resembles paint!
It still needs to be ground finer - I don't have a muller, and using a glass with the flattest bottom I can find isn't exactly doing the job, so I think I'm going to have to get some sandpaper and make myself a muller. (Nobody around here sells them)

This is after grinding down in a mortar and pestle, filtering, grinding some more, filtering (through a tight metal strainer), boiling, letting sit, removing the water from the mix after it separated and filtering that mix through an old t-shirt, adding oil and "mulling" with my glass and/or big palette knife.

It took a surprising amount of oil - I added quite a bit, and it didn't bind, kept going and added a bit more and it started clumping, added a bit more and kept going and it finally started to turn into a paste.

It's still a little gritty, and it feels more like a suspension than a cream... AND I think there was still some water in there... but for a first try I think it's not bad.
I circled it next to the W&N umber.

http://www.wetcanvas.com/Community/images/27-May-2014/1791740-dsg.jpg
Damien, nice work!

What's not working here is your dispersion. It's not very even. It may take a few hours to get even the paint batch right. It takes at least half an hour, for sure – so your arm will get very tired!

You can improvise a muller with a tempered glass paperweight. I got an old paperweight from my grandfather, so I don't know if they make this kind of paperweight anymore. It's a special type of heavy glass that won't break even if you let it drop from around 1 meter.

You're right about that umbers requiring a lot of oil. However, you need to do a swirling motion with your muller too, so that the pigment will crumble more. A signal your dispersion is going ok is when you feel that the linseed you add is "shrinking" – i.e, you can't see as much linseed oil as you added. Your paint should also have an evenness similar to Winsor & Newton's.

A good sign you're doing things right is your muller resisting linseed oil – as if the paint was strongly glued to the glass.

If the water is giving you too much trouble, you can move the aqueous suspension in the glass to an oven at a temperature of 100°C to make the water evaporate. Do not touch the dust immediately after that. Instead, wait for it to cool and add linseed right away, and proceed with the dispersion.

Again, an even dispersion is a critical point in any paintmaking. If you can't do it right, your paint might look lifeless, and might not bind to your medium (linseed oil, in your case.)

Do you have anything that you could use as a muller substitute? Any small, dense glass object with a flat bottom should do.

Regarding your Umber... it shows potential. It's indeed a very cool variety, and when you get things right, it should turn into a very beatiful, transparent low-tinting pigment.

Damienl
05-27-2014, 03:51 PM
Mythrill: I'm going to try again later today. I read somewhere else about someone filtering the finest particles out by putting the mixture in water, shaking it up, and then waiting only a few minutes for it to seperate before pouring off the milky coffee looking top liquid (presumably discarding the bottom heavy minerals and stuff), and pouring that into a new jar.

Is that a good idea? Also, (since I already tried it. No shortage of clay here. Lol) it seems like you could do the pour/seperate/pour/seperate thing forever.

As for a muller I've been trying to find something. I tried an old Pyrex bowl, a glass with the flattest bottom I could find - I actually went to some kitchen stores looking for muller substitutes haha

The only thing I can think of is using wet sandpaper and grinding the bottom of a glass really flat.

Mythrill
05-27-2014, 05:59 PM
Mythrill: I'm going to try again later today. I read somewhere else about someone filtering the finest particles out by putting the mixture in water, shaking it up, and then waiting only a few minutes for it to seperate before pouring off the milky coffee looking top liquid (presumably discarding the bottom heavy minerals and stuff), and pouring that into a new jar.

Is that a good idea? Also, (since I already tried it. No shortage of clay here. Lol) it seems like you could do the pour/seperate/pour/seperate thing forever.


That's the whole point, Damien. :) The boiling with hot water is just so you can make the earth crumble more and allow you to get more of the "good stuff." Shaking would work to a degree, but it wouldn't break the earth as well.

But yeah, you should filter the paint over and over, discarding the larger particles of umber until you get a heavy fine power.

Here's the test: wait for your umber to cool down. After allowing it to settle, touch the bottom of the recipient. You should feel nothing, but when you look at your finger, it should have something that is around the consistency of dust. If you get this consistency, you're on the right track.


The only thing I can think of is using wet sandpaper and grinding the bottom of a glass really flat.

Don't do this. Another purpose of mulling is to break the pigment further while still dispersing. The polished glass might get scratched by the friction between the mulling and the pigment, which is why it would break into even finer particles.

By using wet sandpaper, the finest particles of the pigment (i.e, the very best) will get stuck into the sandpaper and within the scratches of the glass.

Damienl
05-27-2014, 06:23 PM
That's the whole point, Damien. :) The boiling with hot water is just so you can make the earth crumble more and allow you to get more of the "good stuff." Shaking would work to a degree, but it wouldn't break the earth as well.

But yeah, you should filter the paint over and over, discarding the larger particles of umber until you get a heavy fine power.


The first time I boiled it, I let it sit overnight and it separated into perfectly clean water on top and kind of a clay "jello" on the bottom, so I siphoned the water off and poured it through another filter and same thing.

With my "shake" test mix, I took some of the (boiled) clay, shook it up, and poured off the cloudy water into a new container, keeping the cloudy water and discarding the stuff that settled after a few minutes.

That container has since separated again into cloudy water on top, clay on the bottom - but if I pour off the cloudy water though, I'm going to end up with less than a teaspoon of pigment. Boo!

I boiled another batch just now, boiled it longer, ground it finer, and poured the boiled stuff directly through one of those permanent coffee filters into a jar, leaving a LOT of sludge in the filter. We'll see what that settles like!

Here's the test: wait for your umber to cool down. After allowing it to settle, touch the bottom of the recipient. You should feel nothing, but when you look at your finger, it should have something that is around the consistency of dust. If you get this consistency, you're on the right track.



Don't do this. Another purpose of mulling is to break the pigment further while still dispersing. The polished glass might get scratched by the friction between the mulling and the pigment, which is why it would break into even finer particles.

By using wet sandpaper, the finest particles of the pigment (i.e, the very best) will get stuck into the sandpaper and within the scratches of the glass.

No no, I meant to grind the glass flat. I.E. sandpaper stuck to a board, and me sanding the bottom of the glass down to be flat, polishing the glass back up to smooth, and using that to mull with.. Other than that I'm stuck with various dishes... haha

Mythrill
05-27-2014, 07:46 PM
No no, I meant to grind the glass flat. I.E. sandpaper stuck to a board, and me sanding the bottom of the glass down to be flat, polishing the glass back up to smooth, and using that to mull with.. Other than that I'm stuck with various dishes... haha

Yep. I see what you mean. No sandpaper. The dust you get will be so thin that it will get stuck there. The surface needs to be so polished everything glides through it.

I suppose you could add water-based varnish (for oils) or wax (for acrylics) so that the surface will glide, but chances are it'll escape from your hand!

And you're right about getting very little pigment this way: you get the very best umber, but you get very little too.

I've heard about fumed silica being cut with lasers. If you had these, you could filter umber just once or twice and cut it into those small little pieces. But I guess this technology is not available to a regular person. :)

Damienl
05-29-2014, 10:48 PM
Just a little update...
I've tried a few things as mullers. They have not been entirely smooth... as is evident by the bottom of one half of my desk (The closest tempered glass surface I had):

http://www.wetcanvas.com/Community/images/29-May-2014/1791740-IMG_7684.jpg

That said, I spent about an hour attempting to mull. I mulled like there was no tomorrow. Very slowly, over an hour or so.
I ended up with some stuff of paint consistency, however I think it still had water in it (because when I put it in plastic containers to store it overnight, I noticed condensation - maybe a good way to remove water?).
Also, if you took a piece of it and "mulled" it with a pallet knife you ended up with chunky clay again, that wouldn't go back to a creamy paste. The pigment is not binding to the oil enough, too much water still in the paint, I'm guessing the problem is lack of good mulling and not enough mulling... Since that's all I really know about it right now anyway. haha

On the bright side, I did get my first tiny bit of super-fine powdered pigment. It's finer than flour:

http://www.wetcanvas.com/Community/images/29-May-2014/1791740-10300636_10154183097305177_5751603158432266323_n.jpg

Mythrill
05-30-2014, 01:29 AM
Just a little update...
I've tried a few things as mullers. They have not been entirely smooth... as is evident by the bottom of one half of my desk (The closest tempered glass surface I had):

http://www.wetcanvas.com/Community/images/29-May-2014/1791740-IMG_7684.jpg

That said, I spent about an hour attempting to mull. I mulled like there was no tomorrow. Very slowly, over an hour or so.
I ended up with some stuff of paint consistency, however I think it still had water in it (because when I put it in plastic containers to store it overnight, I noticed condensation - maybe a good way to remove water?).
Also, if you took a piece of it and "mulled" it with a pallet knife you ended up with chunky clay again, that wouldn't go back to a creamy paste. The pigment is not binding to the oil enough, too much water still in the paint, I'm guessing the problem is lack of good mulling and not enough mulling... Since that's all I really know about it right now anyway. haha

On the bright side, I did get my first tiny bit of super-fine powdered pigment. It's finer than flour:

http://www.wetcanvas.com/Community/images/29-May-2014/1791740-10300636_10154183097305177_5751603158432266323_n.jpg
Wow, Fabio! You're on the right track! THAT'S how it's supposed to look!

And nice flask, too. :D

You did the right thing to dry the pigment as well. Yes, simply letting the water evaporate will work.

Is that pigment dry? If so, you can begin the dispersion.

As for the muller replacement, I use this type of paperweight. I thought it was no longer sold, but apparently it is:

http://www.wetcanvas.com/Community/images/29-May-2014/96427-blank-crystal-dome-paperweight-glass-half-sphere.jpg

I found this one here: http://www.glorycrystal.com/dome-half-sphere-semisphere-hemisphere/clear-crystal-glass-dome-paper-weight.html.

It seems they sell them, but there's no price listed. In any case, you can probably find something like this somewhere else.

Notice that the upper part is round, but the bottom is flat. This is very important. You make a lot of circular pressure with the top using your two hands, and when the pigment spreads, you do NOT use the palette knife to disperse it, but to bring it back together.

It goes like this: you disperse the pigment, and as soon as it goes "too far," you gather it back with the palette knife. Rinse, repeat.

If you want to prevent oil / pigment separation, you might also want to add up to 5% aluminum stearate to your dispersion.

If you still can't find / can't afford those, I'd suggest trying a small amount of calcium carbonate, which you can do by getting some chicken egg shells, and leave them sit on a pan with vinegar for 24 hours. The vinegar will peel off all the egg skin, which will be suspended. Remove all the skin, pulverize the eggs in your blender, and disperse them as if they were paint (but without the linseed!)

Store the white remainder in a safe place, on a flask with no lid, and let it dry. You should get a fine to medium-coarse white powder, which will be near-transparent in oils. When you start the dispersion of your umber, add some of this inert pigment to your umber and linseed. It'll break into a consistency almost as fine as your Umber– if not finer.

You'll notice the color will lose some of the strength; however, the effect is almost unnoticeable, and the pigment will be much more stable for storage, and this will help preventing the separation.

This "filler white" is transparent in acrylics, but in oils, it's a nearly transparent, pearly gray white. You can mix it with a very small amount Titanium White (of your preference) and get a beautiful, glowing Flake White Hue. Velαsquez sometimes used a mix of both calcium sulphate ("marble dust") and calcium carbonate to increase the transparency of his paintings.

Gigalot
05-30-2014, 09:30 AM
Very nice pigment! But you guys, you must proof, that it is a real umber, powdered iron and manganese oxides and not an organic substance, formed from humic acids. An organic brown pigment has the name Vandyke Brown:

http://www.webexhibits.org/pigments/indiv/overview/vandyke.html

sidbledsoe
05-30-2014, 09:37 AM
Very nice pigment! But you guys, you must proof, that it is a real umber, powdered iron and manganese oxides and not an organic substance, formed from humic acids. An organic brown pigment has the name Vandyke Brown:

http://www.webexhibits.org/pigments/indiv/overview/vandyke.html
I have been reading and thinking along the same lines as Alex, if your source contains much humus then it can yeild a fugitive pigment.

Damienl
05-30-2014, 10:30 AM
Very nice pigment! But you guys, you must proof, that it is a real umber, powdered iron and manganese oxides and not an organic substance, formed from humic acids. An organic brown pigment has the name Vandyke Brown:

http://www.webexhibits.org/pigments/indiv/overview/vandyke.html

What's the method through which you prove which is which?

Gigalot
05-30-2014, 10:41 AM
What's the method through which you prove which is which?

1 The simply method is heating to a high temperature. And if a smoke appears, then there are organic substance.

2 Humic acids gives a red-brown color to a hot KOH or NaOH alkaline solution, while Iron oxides are inert to alkaline.

Damienl
05-30-2014, 10:47 AM
I'll try heating it up. Is it supposed to not smoke, no matter how hot it gets? (Was thinking of using the electric BBQ to test this)

Gigalot
05-30-2014, 11:10 AM
I'll try heating it up. Is it supposed to not smoke, no matter how hot it gets? (Was thinking of using the electric BBQ to test this)

Iron oxides are resistant to heat, yellow oxides turns red at a very high temperature, 700-800 Celsius degree.
I did myself a home-made pigment from crystals, I found on the mountain. I got a very beautiful, transparent brown color. Actually, it was 80% or more an organic substance, rich of sulfur. It can melt and forms a black foam at a high temperature. In oil it is more or less, marginally lightfast, but better or much better than Alizarin Crimson.

Damienl
05-30-2014, 11:24 AM
Iron oxides are resistant to heat, yellow oxides turns red at a very high temperature, 700-800 Celsius degree.

Hmm...I think that might require more than a BBQ. :lol:

Damienl
05-30-2014, 11:40 AM
Thanks a lot for the help and continued info, I really appreciate it!



As for the muller replacement, I use this type of paperweight. I thought it was no longer sold, but apparently it is:

http://www.wetcanvas.com/Community/images/29-May-2014/96427-blank-crystal-dome-paperweight-glass-half-sphere.jpg


Just to be clear - do you use the flat part or the round part to mull the pigment with? (I thought the flat part, but just wanted to be sure)

I've been looking for something to use... the few paperweights I've found so far have been acrylic, but I've been looking at just about everything glass and flat. Even the flattest smoothest glass things I've found are incredibly slightly concave though - almost imperceptibly, but enough that it would suction-cup itself to the mulling surface.

Mythrill
05-30-2014, 01:57 PM
Iron oxides are resistant to heat, yellow oxides turns red at a very high temperature, 700-800 Celsius degree.
I did myself a home-made pigment from crystals, I found on the mountain. I got a very beautiful, transparent brown color. Actually, it was 80% or more an organic substance, rich of sulfur. It can melt and forms a black foam at a high temperature. In oil it is more or less, marginally lightfast, but better or much better than Alizarin Crimson.
But I think that has already been covered, Giga... humus tends to float when do you first filter it with tap water, doesn't it?

There's also the fact that real Van Dyke brown is not only rich in organic matter, but also coal and bitumen. That's not easily found, either. And, overall, it's much redder in its raw form, too. From the photo we got on the bad dispersion Fabio posted, we can see his pigment is distinctly cool (very greenish undertone.)

Mythrill
05-30-2014, 02:04 PM
Thanks a lot for the help and continued info, I really appreciate it!



Just to be clear - do you use the flat part or the round part to mull the pigment with? (I thought the flat part, but just wanted to be sure)

I've been looking for something to use... the few paperweights I've found so far have been acrylic, but I've been looking at just about everything glass and flat. Even the flattest smoothest glass things I've found are incredibly slightly concave though - almost imperceptibly, but enough that it would suction-cup itself to the mulling surface.

Hi, Damien!

Yes, the part that will mull the pigment is the flat part. If you exert enough pressure (which you should,) after a while, the paint will start to get sucked into the lower part, too. This is a sign your dispersion is working.

When you feel the pigment is "gluing" into the flat part, gently and slowly remove it from the glass and use your palette knife to brush the paint away. Then, test the batch.

For the test, even a piece of scrap paper is Ok. If your paint does not separate from oil, and if it's looking like a rich, even color, then that part of the paint is ready and you can begin storing it. If it's not, then return the scrap paint to the glass surface and keep mulling.

Mythrill
05-30-2014, 03:05 PM
I have been reading and thinking along the same lines as Alex, if your source contains much humus then it can yeild a fugitive pigment.
I've thought of answering that question too when I first started mulling my pigment.

You see, this is the umber I got from my yard. This version is being tested with several other pigments in acrylic medium.

These swatches have both the "fried" version and the raw version, and are still from my "bad" batch of dispersion. So far, they have been on a window facing late morning sunlight and early noon exposure.

The photos have been taken with a Nikon D3100 camera, RAW mode (i.e, letting the lens capture every bit of information it can, no compression,) and then color-corrected, as my monitor shows colors as much redder than they should be.

"Clarity" has also been increased, which negates the smoothing algorithm of the camera to some degree, allowing you to see more imperfections on the image (this is good here so you can see every grain of the paint.)

The photo has been scaled down, but kept at 300 dpi. Jpeg was used to save the photo, so I can keep better color fidelity. Compression has been kept to a minimum:

http://www.wetcanvas.com/Community/images/30-May-2014/96427-Raw_Umber_-_8_months_later.jpg

The swatch of the leftmost umber has been not only mixed with titanium white, but also diluted with water as well. Even after 8 months facing sunlight exposure, there has been no color change at all. The same goes for other umbers which you can see closer to it.

By comparison, the yellow you see here is Winsor & Newton's "Azo Yellow Deep" (PY 65.) It has faded in tints and masstone in the beginning, but it remained stable after a while. The color is much less orange than you see in the photo – in real life, it's a very deep yellow-orange. Not even color-correcting the photo completely fixed this.

I'm kinda disappointed by Winsor & Newton's Azo Yellow Deep (PY 65,) by the way. I wouldn't expect it to fade like it did in masstone and undertone so early in the test (3-4 months after continuous exposure.)

A Lemon Yellow (PY 3) by a local brand (Corfix) has been tested together with these watches (not shown here.) It just outperformed Winsor & Newton's PY65, showing no fading even in tints!

Note: this photo doesn't show the parts where Azo Yellow Deep (PY65) faded.

sidbledsoe
05-30-2014, 05:32 PM
that is good, I would test any pigment that I ever dug up too.

Gigalot
05-30-2014, 07:28 PM
humus tends to float when do you first filter it with tap water, doesn't it?


It is not a clay or soil, it is a rock with the hardness more than Gypsum. Fragile, easy to grind black pieces. Color is very gorgeous, I used it much in my paintings in 2011 - 2012 years. I still have a small amount of it.

Mythrill
05-30-2014, 07:53 PM
It is not a clay or soil, it is a rock with the hardness more than Gypsum. Fragile, easy to grind black pieces. Color is very gorgeous, I used it much in my paintings in 2011 - 2012 years. I still have a small amount of it.

A rock? Are you sure, Giga?

The Wiki lists humus just as organic matter. http://en.wikipedia.org/wiki/Humus

It does have a dark-brown color, but it has nothing to do with being a rock.

Mythrill
05-30-2014, 07:59 PM
By the way, this is how Humus usually looks like. Notice it has some very large particles. This is a browner, redder variation.

http://www.wetcanvas.com/Community/images/30-May-2014/96427-composthands.jpg

sidbledsoe
05-31-2014, 01:34 AM
yes, humus is organic material, decomposed leaves etc. hummus is organic too, mashed chickpeas :D

Damienl
05-31-2014, 03:01 AM
Well, I subjected my poor pigment to 3 hours of 750 degrees. No smoke at any point of the process.
The colour changed, here is a tiny bit of original pigment next to some pigment that was cooked dry for 3 hours:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7718.jpg

I also found the best muller I think I'll be able to find - a piece of flat glass from an engraving place. I just bought it sans engraving for $15!

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7711.jpg

NOW the problem I'm having is that when I take my "clay water" and begin to mull it, it all goes great - the water leaves surprisingly fast and as it goes I add linseed oil.
At some point (around the 2 hour mark of mulling I think), it reaches a nice consistency and feels very "paint like". It's still too creamy though - it'll pile and stand up, but it feels like if it were store bought oil paint, it would be thinned a bit with some sort of medium already.
So I mull it another hour, and run into the same problem I always run into - it reverts back to clay. Like, clay you could sculpt with. It seems dry and breaks instead of spreading.

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7712.jpg

I added some more linseed oil, but it no longer "mulls", it just attaches to the muller and slides around my mulling surface on the residue of oil. It's like it de-coupled with the linseed oil or something... I'm not sure what's going on there.

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7714.jpg

I did the only things I could think of to do. Mull it harder, put more pressure on it, work it a bit with the pallet knife, use paper towel to remove linseed oil...but to no avail.

Damienl
05-31-2014, 03:08 AM
Ps. I can tell you that the clay I got came from a few feet below the last signs of any organic matter, plant life, etc. Many feet below the last signs of dirt, and a few feet into the beginning of the layer of clay.

I dug a deep hole. :lol:

Gigalot
05-31-2014, 06:28 AM
Here is this pigment as is:

Gigalot
05-31-2014, 06:40 AM
Ready to gring

Gigalot
05-31-2014, 07:07 AM
Work in progress:

I need to drink a cup of coffee to continue :D

Gigalot
05-31-2014, 08:32 AM
Ps. I can tell you that the clay I got came from a few feet below the last signs of any organic matter, plant life, etc. Many feet below the last signs of dirt, and a few feet into the beginning of the layer of clay.

I dug a deep hole. :lol:

Cooked clay has an attractive color! Raw clay seems to be a kind of brown ochre colored substance.

Mythrill
05-31-2014, 11:16 AM
Well, I subjected my poor pigment to 3 hours of 750 degrees. No smoke at any point of the process.
The colour changed, here is a tiny bit of original pigment next to some pigment that was cooked dry for 3 hours:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7718.jpg

I also found the best muller I think I'll be able to find - a piece of flat glass from an engraving place. I just bought it sans engraving for $15!

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7711.jpg

NOW the problem I'm having is that when I take my "clay water" and begin to mull it, it all goes great - the water leaves surprisingly fast and as it goes I add linseed oil.
At some point (around the 2 hour mark of mulling I think), it reaches a nice consistency and feels very "paint like". It's still too creamy though - it'll pile and stand up, but it feels like if it were store bought oil paint, it would be thinned a bit with some sort of medium already.
So I mull it another hour, and run into the same problem I always run into - it reverts back to clay. Like, clay you could sculpt with. It seems dry and breaks instead of spreading.

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7712.jpg

I added some more linseed oil, but it no longer "mulls", it just attaches to the muller and slides around my mulling surface on the residue of oil. It's like it de-coupled with the linseed oil or something... I'm not sure what's going on there.

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7714.jpg

I did the only things I could think of to do. Mull it harder, put more pressure on it, work it a bit with the pallet knife, use paper towel to remove linseed oil...but to no avail.
Hi, Fabio!

Everything is all right... except for two things.

1. You're using a square surface that's very large. The bottom of your surface should be large, but the surface itself should be small. The reason is that you can exert more pressure by applying less force, and this makes the pigment mulling much easier.

2. You're using paper towel to remove the linseed oil. You should never put it into an absorbent surface and you should not use paper towels to absord it. Each pigment needs different amounts of oil, and umbers may need up to 100%-200% more oil than their relative weight.

Your batch actually needs more linseed oil. Unless you add the medium I told you (beeswax cooked with mineral spirits, which is obviously toxic and requires a respirator because of the fumes,) you will not get the consistency of a paint tube.

Without beeswax and mineral spirits, what you'll get is a "soupy" paint with lots of linseed. It should have a honey-like consistency. The difference is that it disperses and brushes evenly.

I also see you had a lot of trouble into getting a very fine pigment. Since you're starting, go with a very small batch first. Never do your first batches of pigment dispersion with large amounts of paint until you get consistency.

If you stored your pigment in an air-tight place, all you need to do is to slowly add waaaaay more linseed and do a gentle dispersion by this point.

Mythrill
05-31-2014, 11:20 AM
Work in progress:

I need to drink a cup of coffee to continue :D
Hi, Giga.

Indeed, your pigment seems like the real Van Dyke Brown / Cassel earth!

I'm surprised by the metallic sheen it seems to show, though. I know that this pigment usually comes mixed with coal and carbon, but I never heard heard it coming mixed with traces of graphite. Maybe the rock you got was pretty old and some of the carbon converted to graphite over a few thousands of years?

By the way, Fabio: take a close look at Gigalot's pigment consistency. He will still grind it finer, but he just got the consistency right. That's how yours should be.

Damienl
05-31-2014, 11:23 AM
Hi, Giga.

Indeed, your pigment seems like the real Van Dyke Brown / Cassel earth!

I'm surprised by the metallic sheen it seems to show, though. I know that this pigment usually comes mixed with coal and carbon, but I never heard heard it coming mixed with traces of graphite. Maybe the rock you got was pretty old and some of the carbon converted to graphite over a few thousands of years?

I'm curious if it scratches easily with your fingernail... it looks to me like specular hematite, forms of which are the natural iron oxides that are desirable. I get the impression though that you can make a nice pigment out of most forms of it - from what I've learned anyway.

If it's soft and squishy, or scratches deep with your fingernail though, then that theory is out the window. :lol:

Damienl
05-31-2014, 11:36 AM
Hi, Fabio!

Everything is all right... except for two things.

1. You're using a square surface that's very large. The bottom of your surface should be large, but the surface itself should be small. The reason is that you can exert more pressure by applying less force, and this makes the pigment mulling much easier.


True... But this is the best I've found so far.:(


2. You're using paper towel to remove the linseed oil. You should never put it into an absorbent surface and you should not use paper towels to absord it. Each pigment needs different amounts of oil, and umbers may need up to 100%-200% more oil than their relative weight.


Your batch actually needs more linseed oil. Unless you add the medium I told you (beeswax cooked with mineral spirits, which is obviously toxic and requires a respirator because of the fumes,) you will not get the consistency of a paint tube.


I only tried the paper towel as a last ditch effort because when I added more linseed oil, the mixture changed into that tough clay I mentioned - so I tried added even more oil, which had no effect, then tried taking it away.

I'll try added some of the wax in... I wonder if Gamblin's cold wax would work?
It's pure beeswax and mineral spirits, but it does have (they claim) a small amount of alkyd in it.


Without beeswax and mineral spirits, what you'll get is a "soupy" paint with lots of linseed. It should have a honey-like consistency. The difference is that it disperses and brushes evenly.

I also see you had a lot of trouble into getting a very fine pigment. [B][I]Since you're starting, go with a very small batch first. Never do your first batches of pigment dispersion with large amounts of paint until you get consistency.


I definitely get to the soupy honey consistency stage easily - and the pigment did get ground very fine, it doesn't look like it in the photos because it had re-clayed itself into large particles that break apart, looking dry and thick and earthlike.

I'll do a test and take a picture next time before I get to the clay phase (hopefully I wont though!)

My methodology so far has been to take tiny amounts of it, mull it until it reaches say... consistency #1, then scoop it and put it aside, take a new bit and mull that to the same consistency, repeat that a few times until I have a large pile of mulled pigment, then take small bits off the pile and mull more bit by bit, until I have a larger pile that has been fairly uniformly mulled.

I got frustrated in the end and smooshed it all together. :clear:

Mythrill
05-31-2014, 01:07 PM
True... But this is the best I've found so far.:(



I only tried the paper towel as a last ditch effort because when I added more linseed oil, the mixture changed into that tough clay I mentioned - so I tried added even more oil, which had no effect, then tried taking it away.

I'll try added some of the wax in... I wonder if Gamblin's cold wax would work?
It's pure beeswax and mineral spirits, but it does have (they claim) a small amount of alkyd in it.



I definitely get to the soupy honey consistency stage easily - and the pigment did get ground very fine, it doesn't look like it in the photos because it had re-clayed itself into large particles that break apart, looking dry and thick and earthlike.

I'll do a test and take a picture next time before I get to the clay phase (hopefully I wont though!)

My methodology so far has been to take tiny amounts of it, mull it until it reaches say... consistency #1, then scoop it and put it aside, take a new bit and mull that to the same consistency, repeat that a few times until I have a large pile of mulled pigment, then take small bits off the pile and mull more bit by bit, until I have a larger pile that has been fairly uniformly mulled.

I got frustrated in the end and smooshed it all together. :clear:

Hi, Fabio!

I assume the pigment is in soft, clay stage. Is that it?

Here's how you can try to salvage it:

It's perfectly safe to grab this pigment with your hands. What you can do is to get it with your hands, break it apart (as if you were tearing small pieces of modeling clay apart,) and then add some mineral spirits to dissolve some of the linseed and gently disperse it (i.e, not adding strength nor pressure to it.) This should improve your pigment consistency.

If all else fails, you can still store the pigment you made into an air-tight container and dissolve bits of it later with a combination of mineral spirits, linseed oil and a palette knife. :)

Mythrill
05-31-2014, 01:09 PM
By the way, you got an interesting burnt hue, too. Mine was definitely different. The raw pigment was yellower, and the burnt version was redder. Your burnt hue seems almost violet.

Could you take some of the pigment and and mix it with a few colors on scrap paper so we can see how it behaves?

Damienl
05-31-2014, 03:12 PM
Hi, Fabio!

I assume the pigment is in soft, clay stage. Is that it?

Here's how you can try to salvage it:

It's perfectly safe to grab this pigment with your hands. What you can do is to get it with your hands, break it apart (as if you were tearing small pieces of modeling clay apart,) and then add some mineral spirits to dissolve some of the linseed and gently disperse it (i.e, not adding strength nor pressure to it.) This should improve your pigment consistency.

If all else fails, you can still store the pigment you made into an air-tight container and dissolve bits of it later with a combination of mineral spirits, linseed oil and a palette knife. :)

That is so obvious I can't believe I didn't think of it!

What I ended up doing was taking a bit of the pigment that had gone from honey-like back to clay, adding more oil and mulling it more, to no avail, then I added the tiniest (and I mean tiny - the size of a grain of rice) amount of Gamblin's Cold Wax to it, and it almost immediately became lipophilic and went from looking saturated in oil to a paste that soaked up even more linseed oil, and went back to a honey like state.
I mulled it for another 20-30 minutes and spread it on the glass:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7721.jpg

Still a bit of course stuff in there but all in all, waaaay better.
This is it on one of those shiny covered paper disposable pallets, heaped on, spread with a pallet knife, brushed thickly, thinly, every which way:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7722.jpg

Pretty cool! I am definitely getting closer!

By the way, you got an interesting burnt hue, too. Mine was definitely different. The raw pigment was yellower, and the burnt version was redder. Your burnt hue seems almost violet.

Could you take some of the pigment and and mix it with a few colors on scrap paper so we can see how it behaves?

Sure - I'll cook the rest of my powdered stuff tonight when it's a bit cooler, so I have enough to test out with different things.
I'm not sure how well it'll respond to mixing since it has such a low tinting strength, but it'll be interesting to see.

Mythrill
05-31-2014, 06:57 PM
That is so obvious I can't believe I didn't think of it!

What I ended up doing was taking a bit of the pigment that had gone from honey-like back to clay, adding more oil and mulling it more, to no avail, then I added the tiniest (and I mean tiny - the size of a grain of rice) amount of Gamblin's Cold Wax to it, and it almost immediately became lipophilic and went from looking saturated in oil to a paste that soaked up even more linseed oil, and went back to a honey like state.
I mulled it for another 20-30 minutes and spread it on the glass:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7721.jpg

Still a bit of course stuff in there but all in all, waaaay better.
This is it on one of those shiny covered paper disposable pallets, heaped on, spread with a pallet knife, brushed thickly, thinly, every which way:

http://www.wetcanvas.com/Community/images/31-May-2014/1791740-IMG_7722.jpg

Pretty cool! I am definitely getting closer!



Sure - I'll cook the rest of my powdered stuff tonight when it's a bit cooler, so I have enough to test out with different things.
I'm not sure how well it'll respond to mixing since it has such a low tinting strength, but it'll be interesting to see.
Wow, Fabio! It's just so beautiful.

You're not closer. You're spot-on! What quantity of mineral spirits did you add?

In masstone, your umber resembles the results I got in acrylics. It's a bit warmer because of the linseed oil.

You won't be able to get rid of all of the grains – but why should you? The grains we can see when you spread your paint are similar to what can be seen in industrial-grade pigments (like Yellow or Transparent Red Iron Oxide!)

I can still see the cooler cast of the pigment, though. The natural pigment you describe is what I got a while ago, too: very low tinting, and very transparent.

I haven't seen the results yet, but I suppose your umber will give you even cleaner mixes than mine did!

Damienl
06-01-2014, 03:26 AM
Here's the stuff mixed with Rembrandt titanium white. Starting off with very little because titanium white would make this stuff dissappear pretty quick.

On top is the raw paint, on the very bottom is raw white. Just above the naked white, the little swatch you can barely tell is different from the white, is where the mix reached a 1:1 ratio.
I'm really surprised by the neutrality of it I have to say. Not as much green tinge as I expected.

http://www.wetcanvas.com/Community/images/01-Jun-2014/1791740-IMG_7741.jpg

I'm currently cooking some pigment to try tomorrow.
I also took a little field trip today with my bag and collapsible shovel... Now, I'm first to admit I know nothing about rocks.
So I used the highly scientific method of picking up rocks I didn't recognize, scratching them against something to see if they left any color, and throwing them back if they didn't.

I found a bunch of interesting stuff! No idea if it's useful. But interesting!

http://www.wetcanvas.com/Community/images/01-Jun-2014/1791740-IMG_7730.jpg

The yellow orangy rock on the very left leaves a very neutral pale yellow mark. All the rest leave a variety of marks. Some of the redder stones leave red marks - but some stones that are not red leave red marks as well. Half of them I'd only call stones because I don't know the proper word for what they really are - some sort of crumbly, stone-looking thing.

Some of the black stones are shiny (glass like) in places, and some of them are matte. The two on the far right are rock-like, but I'm pretty sure they are clay that the river has worked over enough that they've become that way. They left marks that looked very umber-y, so I grabbed them too.

Not sure whether to figure out what they are, or just go ahead and try and make paints out of some of them and see how it goes. :lol:

Gigalot
06-01-2014, 06:09 AM
Hi there! Damienl, orange and rose rocks are gorgeous pigments :thumbsup: and your paint from clay has nice greenish brown undertone! :clap: Great verdaccio color!

Finally I got a fine creamy pigment and let it to dry:

Mythrill
06-01-2014, 12:05 PM
Here's the stuff mixed with Rembrandt titanium white. Starting off with very little because titanium white would make this stuff dissappear pretty quick.

On top is the raw paint, on the very bottom is raw white. Just above the naked white, the little swatch you can barely tell is different from the white, is where the mix reached a 1:1 ratio.
I'm really surprised by the neutrality of it I have to say. Not as much green tinge as I expected.


Hi, Damien!

It's your pigment is neutral in masstone mostly because of linseed oil. It definitely changes some colors. One example is the orange-ish red iron oxide I have here (sold as house bricks.)

In powder and aqueous state, the red iron oxide has a beautiful, scarlet tone. But when you add linseed oil to it, it becomes a deep, brownish red. Winsor & Newton documents this very well: their PBk 31 is called Perylene Black in oils, but Perylene Green in watercolors and acrylics!

This is why some manufacturers use nut, poppy or safflower oil on some or all their colors. The ones that use it on just some reserve it for their whites, blues and violets, usually.

I also one of the swatches where you mix your umber with titanium white so Photoshop can help us telling what shade it is exactly.

http://www.wetcanvas.com/Community/images/01-Jun-2014/96427-Swatch_1.jpg

If you consider RGB as the colors being reflected, we have an approximated value as R = 138, G = 126 B = 100.

No surprise here. It's a near-neutral undertone, as all the values are very close. But since red and green make yellow in photoshop's system, we can say your Raw Umber has a predominant yellow shade (Y + G = 264.) There's also a strong cyan cast too, though (B + G = 226!)

I tried match this color against the PANTONE system. However, there's no exact match. The closest I get to is a lighter hue.

Golden's Virtual Paint Mixer approximates this by 40% Titanate Yellow (PY 53,) 10% Violet Oxide (PR 101,) and 50% Neutral Gray N6, which is basically Titanium White (PW 6), Bone Black (PBk 9), and... an undiscoled Umber (PBr 7.)

Meaning: it's impossible to replicate this hue at this very spot without using at least some sort of umber in the mix.

It also seems that wherever I click, there's almost always some sort of Umber or Neutral Gray (which involves umber) included.



I'm currently cooking some pigment to try tomorrow.
I also took a little field trip today with my bag and collapsible shovel... Now, I'm first to admit I know nothing about rocks.
So I used the highly scientific method of picking up rocks I didn't recognize, scratching them against something to see if they left any color, and throwing them back if they didn't.

I found a bunch of interesting stuff! No idea if it's useful. But interesting!

http://www.wetcanvas.com/Community/images/01-Jun-2014/1791740-IMG_7730.jpg

The yellow orangy rock on the very left leaves a very neutral pale yellow mark. All the rest leave a variety of marks. Some of the redder stones leave red marks - but some stones that are not red leave red marks as well. Half of them I'd only call stones because I don't know the proper word for what they really are - some sort of crumbly, stone-looking thing.

Some of the black stones are shiny (glass like) in places, and some of them are matte. The two on the far right are rock-like, but I'm pretty sure they are clay that the river has worked over enough that they've become that way. They left marks that looked very umber-y, so I grabbed them too.

Not sure whether to figure out what they are, or just go ahead and try and make paints out of some of them and see how it goes. :lol:

Be careful with what you use! Even though these are all rocks, not all them will break or stable in oil painting!

Some of your rocks seem natural forms of Light Red (PR 102.) Others seem to have some sort of calcium material, and the gray one at the very top seems to be an iron ore – if you manage to break it, it will give you an unstable gray color that's prone to convert into an iron oxide!

I've read of two recipes to convert iron into iron oxide. I know of one that certainly does work, but you must be careful.

Method 1:
It consists of turning a car on and putting two wires from the battery in water. Note that you must also add salt into it. The electricity will accelerate the corrosion of iron and convert it into Red Iron Oxide (PR 101.)

Method 2:
Warning: wear a respirator and do this outside your house!

Get your iron ore and a non-metal recipient (glass or plastic, if possible.) Place your iron ore there. Then, throw caustic soda (undiluted) into it. Your iron ore will decompose into Yellow Iron Oxide (PY 42) over time.

An additional challenge with this method is that you must get the yellow powder and make sure you wash any leftover salts away. They will not go away by evaporation. The most reliable method to do this would be a laboratory centrifuge, but you could also try filtering using some sort of fabric. The problem is that, if the fabric doesn't corrode, chances are the pigment will be stuck into it.

Failure to do so will result in a pigment that will corrode your brushes into soap and render any oil paint you try to make useless!

Mythrill
06-01-2014, 12:08 PM
Hi there! Damienl, orange and rose rocks are gorgeous pigments :thumbsup: and your paint from clay has nice greenish brown undertone! :clap: Great verdaccio color!

Finally I got a fine creamy pigment and let it to dry:

That's a very beautiful, greenish material, Giga. I didn't expect the greenish tint I see here. Did you add something to the mix?

As a side note, your paint has a distinct, beautiful metallic sheen (as I mentioned before.) Do you know where it is coming from?

Mythrill
06-01-2014, 12:12 PM
Damien, I also forgot to say. As you saw yourself, the umber you got has a very low tinting strength. That means it's best not to use pure titanium white, even at small quantities. Try to use oil gel medium mixed to around 5-10% titanium white and mix that into the umber if you want to use it solo.

Damienl
06-01-2014, 02:27 PM
Be careful with what you use! Even though these are all rocks, not all them will break or stable in oil painting!

Some of your rocks seem natural forms of Light Red (PR 102.) Others seem to have some sort of calcium material, and the gray one at the very top seems to be an iron ore – if you manage to break it, it will give you an unstable gray color that's prone to convert into an iron oxide!

I've read of two recipes to convert iron into iron oxide. I know of one that certainly does work, but you must be careful.

Method 1:
It consists of turning a car on and putting two wires from the battery in water. Note that you must also add salt into it. The electricity will accelerate the corrosion of iron and convert it into Red Iron Oxide (PR 101.)

Method 2:
Warning: wear a respirator and do this outside your house!

Get your iron ore and a non-metal recipient (glass or plastic, if possible.) Place your iron ore there. Then, throw caustic soda (undiluted) into it. Your iron ore will decompose into Yellow Iron Oxide (PY 42) over time.

An additional challenge with this method is that you must get the yellow powder and make sure you wash any leftover salts away. They will not go away by evaporation. The most reliable method to do this would be a laboratory centrifuge, but you could also try filtering using some sort of fabric. The problem is that, if the fabric doesn't corrode, chances are the pigment will be stuck into it.

Failure to do so will result in a pigment that will corrode your brushes into soap and render any oil paint you try to make useless!

Eep!
I went through the rocks at home today and threw out most of them, keeping a handful. A couple light red (almost like brick mixed with white) soft rocks were a no brainer, a darker rock that breaks down easily and quickly in the mortar into a nice darker red, some thin rocks that I'd guess contain calcium, which I ground up with no regard to whether they're useful or not, and a few different ones that were clearly clay.
I threw away anything that didn't break easily with a hammer, and all the blacks after reading the possibility of them containing lead.

I'm going out again today to look for more (of course) so that I can try making some into paint, and also try experimenting with burning some.

I discarded the rocks (there were a couple not in the picture) you thought were iron ore - Are there any similar pitfalls you can think of off the top of your head I should avoid?

I'll be testing all my paints on a canvas board with brushes I don't care about, for paintyness (that's a technical term), lightfastness, but I don't know if there's a way to really test their performance over time.

Maybe mix some of the raw pigment powder with something easily eaten away by a pigment that could be detrimental.

Mythrill
06-01-2014, 04:01 PM
Eep!
I went through the rocks at home today and threw out most of them, keeping a handful. A couple light red (almost like brick mixed with white) soft rocks were a no brainer, a darker rock that breaks down easily and quickly in the mortar into a nice darker red, some thin rocks that I'd guess contain calcium, which I ground up with no regard to whether they're useful or not, and a few different ones that were clearly clay.

Keep those light red rocks at a safe and throw away the password!

If those are natural red iron oxide, they're a real treasure. It's harder to predict what exactly their hue will be – even more so than than any Raw Umber. They're usually much less opaque than their synthetic varieties, but you can get very beautiful tones that range from pinkish to orange.

I have (in acrylics) what Winsor & Newton calls "Light Red (PR 102). It's one of their unique paints in Artists' Acrylics. I think it's very odd they only sell it in this very line. When you see the swatch at dickblick.com, it looks just like most synthetic iron oxides – well, brick-like.

When I did get the tube in my house, though, it was a completely different story. Yes, in masstone the paint resembled a lighter version of synthetic "Red Iron Oxide" (PR 101.) Much to my surprise, though, the tints behaved like a desaturated version of Cadmium Red Light (PR 101), and, in fact, it could even pass as Cadmium Red Light in a low-chroma palette!

The brands that offer this exact shade are very, very rare. Old Holland gets a similar hue in oils (called "Flesh Ochre") by mixing Naphtol Scarlet (PR 112) to Red Iron Oxide (PR 101,) but Naphtol Scarlet might fade in tints.

You could try sending some of this red pigment to the oven to see if it gets orange. Most likely, though, it will get a bit violet. If the yellow rocks you got are a variety of Yellow Ochre, you can control the hue you get by trying to baking it and getting an orange, or mixing the Raw / Baked pigments (without dispersion) to your Red Ochre.

This is how companies control the hue of their earths without changing the vibrancy and composition. If you try hard enough, it's very likely you'll get the much-envied orange-ish red ochre!


I threw away anything that didn't break easily with a hammer, and all the blacks after reading the possibility of them containing lead [...]

In what country do you live? It's very unlikely to find lead on the surface of the earth. Its mineral form usually has to be mined.

Even though those rocks might not be usable, they're far more likely to be simply iron ores or quartz / silica crystals with impurities that make them black. If you live near the sea, it's even less likely this is actually lead and far more likely this is quartz / silica (which are abundant near seashores.)



I discarded the rocks (there were a couple not in the picture) you thought were iron ore - Are there any similar pitfalls you can think of off the top of your head I should avoid?

I can only think of a few. Bitumen (makes your painting crack over time,) Cassel Earth (might fade if it has too much lignite and if it's not used carefully,) or rocks near very dirty rivers (heavy metal pollution due to waste.) You're most likely to run into rocks that will be too hard or too transparent in oil form (making them unusable.)

I'd suggest showing any rocks you don't recognize here so we can try to help you to identify them.



I'll be testing all my paints on a canvas board with brushes I don't care about, for paintyness (that's a technical term), lightfastness, but I don't know if there's a way to really test their performance over time.

To test for lightfastness, Just do what handprint.com does: accelerated lightfastness aging. Paint two different sheets of paper with swatches of your paint full strength, then a swatch mixed with 50% Titanium White (less, in the case of your Raw Umber, considering it has a very low tinting strength,) and a swatch diluted with mineral spirits and linseed oil.)

Wait for both swatches to dry. You'll keep one swatch hidden from sunlight, in a drawer, for one year, and you'll stick the other in a window, facing as much sunlight as possible (preferably afternoon, which is the most harmful.)

Check the swatches every month for at least 12 months. The longer the paint takes to fade, the most lightfast it is. Take a few photos if you want and compare them too.

If you do take photos, though, make sure to correct the hue, brightness and contrast to match your samples!

Each month is equivalent to 10 years of museum light. If your paint does not fade for 12 months, it means it can handle 100 years without changing, meaning it's Blue Wool Scale 8 (best!)

Of course, you can keep testing your samples for as long as you can. Ochres and umbers are known for not fading for thousands of years, the oldest examples being cave paintings of 40,000–50,000 years ago!


Maybe mix some of the raw pigment powder with something easily eaten away by a pigment that could be detrimental.
Do you mean trying to provoke a reaction that would cause a pigment to fade?

Those tests, by themselves, are not very reliable if done carelessly. Ultramarine Blue, for instance, can certainly withstand thousands of years in the desert (the oldest examples being Egyptian paintings 2,000–3,000 years ago,) but they will easily fade if you throw a mild acid on them!

Unless you're going for external painting (e.g, painting the walls of your house,) it's not worth testing for this, as your painting is very likely to be kept indoors, protected from rain and humidity. If you do want to try, though, your best bed is to simulate something like acid rain. This way, you'll test for weatherfastness (resistance to weather.)

Even on those conditions though, iron oxides are very stable. It's more likely the binder of your paint will fall off from the wall than your paint will discolor.

Mythrill
06-01-2014, 04:48 PM
By the way, I followed a modified Golden recipe mix to show how special your Umber is – despite being a near-neutral!

Since not all my colors are from Golden and I don't have their premixed neutral grays, I followed these recipes to imitate your umber in masstone and tints with white. I chose "Transparent Yellow Iron Oxide" to cover some of the gamut that Umbers do, and also because they're the most saturated inorganic ochre colors you can find in acrylics.

Mix 1:
Nickel Titanium Yellow (PY 53) – Daler-Rowney
Violet Iron Oxide (PR 101) – Winsor & Newton (Artists' Acrylics)
"Ivory" (Bone) Black (PBk 9) – Winsor & Newton (Artists' Acrylics)
Transparent Yellow Iron Oxide (PY 42) – Corfix (local brand, cheaper line)Mix 2 (Higher Chroma):
Quinacridone Gold (PO 48 + PY 150) – Daniel Smith
Quinacridone Violet (PV 19-beta) – Winsor & Newton (Finity)
"Ivory" (Bone) Black (PBk 9) – Winsor & Newton (Artists' Acrylics)The photo was downscaled to fit the forums, but kept at 300 dpi. Taken with Nikon D3100, RAW. Saved to JPEG, minimum compression. Increased "clarity" and "exposure."


Please note that contrary to film cameras, digital cameras will try to round colors near them to an average. This tends to obliterate the subtle differences between similar color hues. In this case, I've divided each mix into a row and color-corrected each of them to match what I see on paper. The results are still not 100% accurate, though!



http://www.wetcanvas.com/Community/images/01-Jun-2014/96427-Raw_Umber_mix.jpg
Column 1 – followed recipe 1, as described above. This gave me a very opaque umber hue. To match the actual umber original sample in my notebook, I had to add lots of Ivory Black (PBk 9). The result is a color with a greener cast in masstone, but very desaturated compared to actual umber.
Column 2 – followed recipe 1, but added more Violet Iron Oxide (PR 101) to make it warmer, and more Transparent Yellow Iron Oxide (PY 42) to make it more transparent, combined with Ivory Black (PBk 9) to darken a bit more and increase transparency. The result is more saturated, but much redder too – and tints with Titanium White (PBk 9) simply don't shift to the more greenish tone.
Column 3 – tried recipe 2, which involves almost only transparent pigments to make it more transparent. The result is still an umber hue with a very huge covering power – not as huge as the two other two recipes, but still quite huge. Fair enough: the result is darker, richer and more saturated, but mixing it with white will give me a reddish hue with an odd yellowish cast (because of the Quinacridone Gold in the mix.)
Column 4 – added gel medium (supposedly matte) to reduce the tinting strength of the mix of column 2 and tried to get it to behave more like actual Raw Umber (PBr 7.) Instead, the color shifted even more to violet and red, and tinting it didn't give me the delicate silvery grays Raw Umber does; instead, the mix shifted to a reddish tone.I'm pretty sure at least columns 2 and 3 are eerily similar to the tubed paints you have, right Damien?

By the way, could you mix your paint with a lemon yellow (PY 3, PY 35, etc) and compare it with the paint tubes you've got? I'd love to see how similarly (or differently) they mix!

Damienl
06-02-2014, 02:32 AM
Keep those light red rocks at a safe and throw away the password!

If those are natural red iron oxide, they're a real treasure. It's harder to predict what exactly their hue will be – even more so than than any Raw Umber. They're usually much less opaque than their synthetic varieties, but you can get very beautiful tones that range from pinkish to orange.


Unfortunately I don't know how to tell if they are or aren't - but you can see them ground up below.


In what country do you live? It's very unlikely to find lead on the surface of the earth. Its mineral form usually has to be mined.

Even though those rocks might not be usable, they're far more likely to be simply iron ores or quartz / silica crystals with impurities that make them black. If you live near the sea, it's even less likely this is actually lead and far more likely this is quartz / silica (which are abundant near seashores.)


I'm in Ottawa, Canada. Nowhere near a sea, but I am near a river and there's apparently all sorts of stuff I can find around here, if I figure out where. Right now my approach is more the "Let's go look by the river. Hey, that big channel full of weeds and horrible things to climb through looks like it might have been a river once! Lets climb down there and dig a hole and hope nobody sees me and calls the mental ward. :lol:


I'm pretty sure at least columns 2 and 3 are eerily similar to the tubed paints you have, right Damien?


Column 2 looks very close indeed!


By the way, could you mix your paint with a lemon yellow (PY 3, PY 35, etc) and compare it with the paint tubes you've got? I'd love to see how similarly (or differently) they mix!

Sure thing, I'll mix some lemon yellow w/ my paint and W&N's umber to compare.
I was going to mull the pigment I baked last night, but today was looking-for-more-stuff day.

I went looking for rocks, going up and down the few places I could find anything along the river. (The river rose recently to really, really high levels and hasn't gone all the way back down yet, so the pickings are slim.)

These are what I got out of my trip. Aside from one (the brightest one, which was very crackly and chippy and calcium-like), these were all soft rocks that you could literally just draw on things with if you wanted to. A few colours are very similar, but I kept each rock in it's own vial because although similar in colour, some came from rocks with different properties.

http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-P6010005.jpg

I used my real camera to take this picture because an iphone didn't pick up on the subtle colours. Even with my real camera, the picture doesn't accurately display the pigment - probably because it's late and night and I had only one light sourse on, and the bulbs in the ceiling do not have a high CRI. And also, LED bulbs have a very strange, very digital spectrum of light they emit.
Either way, I'm rambling now (I'm a photographer/videographer, I can talk about lights forever. Here's my site (http://damienlaliberte.com) if you wanna look at any of my stuff! Haha

Here's a pic with the iphone for comparison. If you averaged the values out, you'd probably be closest to the actual colour of everything.

http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-IMG_7745.jpg

Mythrill
06-02-2014, 10:38 AM
Lets climb down there and dig a hole and hope nobody sees me and calls the mental ward. :lol:

I think the same when I go around my house to gather chips of red bricks (bricks here are made of red, scarlet hematite!)



These are what I got out of my trip. Aside from one (the brightest one, which was very crackly and chippy and calcium-like), these were all soft rocks that you could literally just draw on things with if you wanted to. A few colours are very similar, but I kept each rock in it's own vial because although similar in colour, some came from rocks with different properties.

http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-P6010005.jpg

I used my real camera to take this picture because an iphone didn't pick up on the subtle colours. Even with my real camera, the picture doesn't accurately display the pigment - probably because it's late and night and I had only one light sourse on, and the bulbs in the ceiling do not have a high CRI. And also, LED bulbs have a very strange, very digital spectrum of light they emit.
Either way, I'm rambling now (I'm a photographer/videographer, I can talk about lights forever. Here's my site (http://damienlaliberte.com) if you wanna look at any of my stuff! Haha

Here's a pic with the iphone for comparison. If you averaged the values out, you'd probably be closest to the actual colour of everything.
[/quote]

Well, all flasks from behind seem like umbers. The two in the front and left seem like yellow varieties of yellow ochre – the first one even resembles the synthetic Gold Ochre (PY 42) Winsor & Newton has!

The one right next to it seems a bit more lemony, and the other seems to have traces of ochre, but being almost white. I suppose you could mix the two to get lemon ochres of varying degrees.

The last 2 tubes are very interesting, and I don't seem to have these around. The first tube from right to left seems like a different form of calcium. I suppose it's very likely to be calcite, but I don't know. The pigment on the left seems to be a very weak form of Green Earth (PG 23,) which could be mixed to the umbers in very small proportions to give you a green like paint that could be used for portraiture.

Does anyone else have any ideas of what these pigments may be

By the way, if you want to shift your umbers to a green shade manually, buy some manganese dioxide (with the formula MgO2.) It's very cheap. Here, you can find 500g by around $ 10. That's what makes umbers have a green cast. Just get a little mask (like the one used when you have a cold) mix up to 20% MgO2 relative to the quantity of umber you have (if you have 100g of umber, add 15g-20g of MgO2.) This should not affect none of the handling qualities of your umber except for the hue.

Mythrill
06-02-2014, 01:14 PM
Just to correct a little detail: I accidently wrote Mg. Mg is "Magnesium." Manganese is Mn, so you want MnO2.

Damienl
06-02-2014, 02:16 PM
The last 2 tubes are very interesting, and I don't seem to have these around. The first tube from right to left seems like a different form of calcium. I suppose it's very likely to be calcite, but I don't know. The pigment on the left seems to be a very weak form of Green Earth (PG 23,) which could be mixed to the umbers in very small proportions to give you a green like paint that could be used for portraiture.

I bet you're right about the second one. The first one has me stumped too, it seems like it'd have calcium just because...it seems like it would. It was the rock in the center of this pic:

http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-IMG_7735.jpg

It was very brittle, and in scales/layers/formations. Breaking it was a lot like smashing a really thick seashell.

Here's my umber mixed with Winton Cadmium Lemon Yellow. The W&N raw umber is mixed in about a third of the proportion compared to my umber, do to it's tinting strength.
Cad yellow untouched on top, then 3 mixes, then the straight umbers, then brush strokes.

http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-IMG_7747.jpg

Edit: I'm not sure what it is about how I'm making it, but my umber is not as fast a drier as umbers tend to be. It's about 3 days to dry here, in high heat and low humidity.

Gigalot
06-02-2014, 05:11 PM
Golden pigment powder looks gorgeous. Miracle orange color!

Mythrill
06-02-2014, 05:38 PM
http://www.wetcanvas.com/Community/images/02-Jun-2014/1791740-IMG_7747.jpg

Edit: I'm not sure what it is about how I'm making it, but my umber is not as fast a drier as umbers tend to be. It's about 3 days to dry here, in high heat and low humidity.
I knew it! Your umber makes that beautiful "green gold" tone! It's just so lovely... :D

The mixes seems almost identical to Winsor & Newton's umber in masstone, but when you see it in tints (brush strokes,) your umber tells another story: because of the lower tinting strength, it gives a clearer yellow-green, and it granulates a bit, too.

The slower drying is probably happening because you didn't add any siccatives to your paint. In the case of a real umber, that's actually very desirable if you're going to store it. The content of MnO2 might also be a bit low (lower than 10%.) The greener the umber, the faster it dries (as MnO2 is an oxidizer and siccative.)

By the way, since you didn't find natural red ochre, you could bake some of your yellow ochres in the oven (e.g, the golden one,) just like your umber. You'll get a gorgeous red umber. :)

Just be careful to keep an eye on it. The longer you bake it, the longer the darker it'll be until it turns violet, and finally, black (Natural Hematite, PBk 11)!

Mythrill
06-02-2014, 05:40 PM
Golden pigment powder looks gorgeous. Miracle orange color!

Isn't it, Giga? :)

As I said, Winsor & Newton has a synthetic version they call "Gold Ochre" (PY 42,) but this particular shade is only in their Professional Acrylics line.

Depending on how it mixes with linseed, it could make a shimmering golden brown. :D

Gigalot
06-03-2014, 05:08 AM
I heard, that yellow ochre heating at a temperature 560 - 600 Celsius degree gives orange-red color to pigment, while heating at 750 - 800 Celsius degree (and with cooking salt additive) gives red-violet color to it.

Damienl
06-03-2014, 06:05 AM
I heated up a few piles of stuff, and the results were cool!

Before:

http://www.wetcanvas.com/Community/images/03-Jun-2014/1791740-before.jpg

After:

http://www.wetcanvas.com/Community/images/03-Jun-2014/1791740-after.jpg

I think I'm gonna have to try this with all my beige type pigments to see if something happens...because one only needs so much beige powder...

Question for anyone who knows... If you have two very similar colours, is it ok to mix them? Even if they come from different types of rocks?

Is there anything you shouldn't mix?

Gigalot
06-03-2014, 06:20 AM
Great result! Ottawa can be a new Luberon! These Red-Yellow earth pigments are Iron oxides, all are very lightfast colors, inter-mixable and absolutely permanent.

Mythrill
06-03-2014, 10:12 AM
I heated up a few piles of stuff, and the results were cool!

Before:

http://www.wetcanvas.com/Community/images/03-Jun-2014/1791740-before.jpg

After:

http://www.wetcanvas.com/Community/images/03-Jun-2014/1791740-after.jpg

I think I'm gonna have to try this with all my beige type pigments to see if something happens...because one only needs so much beige powder...

Question for anyone who knows... If you have two very similar colours, is it ok to mix them? Even if they come from different types of rocks?

Is there anything you shouldn't mix?

Damien, it's absolutely ok to mix them! As Giga said, they're all iron oxides. And when you mix then in powder form (as opposed to mixing dispersed paint,) there will be no loss of saturation – meaning your mix will be as chromatic as a single pigment!

Just make sure to mix them evenly and not to breathe the dust.

I see the leftmost pigment on the bottom on the first photo turned much greener, essentially making it a Green Earth (PG 23), which is quite rare. What was the corresponding raw pigment?

The leftmost pigment on the bottom of the second almost screams Red Ochre (PR 102). Try to make a very small batch of oil paint and check the hue. If the tints are scarlet, it's also a rare pigment!

Gigalot
06-03-2014, 01:42 PM
Hi, Mythrill, you can check miner dumps if these available in your region.

I heard, that Minas Gerais miner dumps are rich from different iron oxides, ochres, hematite, goethite/limonite e.t.c natural pigments :thumbsup:

http://www.mining-technology.com/projects/carajas/carajas2.html

Mythrill
06-03-2014, 03:39 PM
Hi, Mythrill, you can check miner dumps if these available in your region.

I heard, that Minas Gerais miner dumps are rich from different iron oxides, ochres, hematite, goethite/limonite e.t.c natural pigments :thumbsup:

http://www.mining-technology.com/projects/carajas/carajas2.html
Hi, Giga.

That mine is a bit distant from here, but we also mine iron ore. I can find the pigment easily, but not in its purest state. :)

It's more time-consuming to me to filter all the impurities I find with iron oxides (like quartz, for instance.)

Damienl
06-04-2014, 02:49 AM
So, this is a hell of a lot of fun.
Now I have to find a source of green, blue, and white... that aren't highly toxic...

I really like cooking powders. Grinding them really well, cooking them for 750 degrees for 3-4 hours, then sifting them through a replaceable coffee filter into a jar produces a pigment that is ingredable fine, and with a bit of oil it mulls SO much more easily than the wet solution I've been working with with the umber I dug out of my back yard. I'm gonna try drying some of it out, but I doubt it'll work as well as grinding a rock down...

I still can't tell what's gonna happen when I cook different pigments. Usually they turn redder, some turn orange, some dark ones lighten up, some do nothing, one turned a very deep red with a violet base.

Before:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-bef.jpg

After:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-af.jpg

I also found a use for the silt that you filter out of pigment mixed in water:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-IMG_7765.jpg

I've been trying to get the most out of my pigments as I can - I grind them super fine, sift them through a fine strainer, grind the stuff that didn't go through the sifter, sift again, put it in water, let it settle and pour the top off,

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-IMG_7770.jpg

pour the silty heavy stuff that fell to the bottom into my mortar and grind it some more, pour it back into the jar of pigment and water... then filter the pigment by letting it separate and pouring off the top many times over several days.

This seems to give me the best success so far...
There are a few rocks though, that can just be ground up and sifted and are fine enough to be mulled right then and there. No idea what the difference is. :confused:

I've figured out that the best source of rocks around here seems to be areas around the river, right after rapids/falls but before the water slows down. The fast moving water seems to bring all sorts of rocks up, but by the time it turns into a slow river, there's just river rocks and mud.

I gotta go find some more places to look now!

Much thanks to Mythrill, Gigalot. You guys shared a lot of very useful knowledge with me, and now I can make an entire pallet of brick shades and umbers! :lol:

The biggest thing I have to figure out now is how to accurately prep pigments from their natural state to ready-to-mull... Clay is easy enough with the water settling method, and so are some of the pigments I've found around. But some of them (the nicest looking, of course - bright orangey-red naturally) when ground incredibly fine and mixed with water, eventually just seperate completely.

So there's just clear water on top, and the dust on the bottom. :/
I've had that happen with orangey-red rocks that broke apart easily, and with beige and light brown stones that required a bit of tapping with my pestle.

Not sure what to do there, as they're not ready to mull after grinding, but in water they just cleanly seperate. o.O

Any suggestions?

Ps. Sorry for the enormous run-on post!

Gigalot
06-04-2014, 06:10 AM
These bright orange and rose rocks are looking like iron-rich argillite like here:

http://www.agefotostock.com/en/Stock-Images/Rights-Managed/ACX-acp50927

If you have a rock, and not a soil or dirty clay with a lot of impurities, sand, e.t.c you do not need to wash it. Sedimentation and decanting is not necessary to make pigment from it. Stone is a pure pigment. Just grind it with water until a fine or finest powder appears, dry it and store in a glass jar. And after that you can make an oil paint from it, just mix it carefully, using spatula, with pure, solvent free, wax free, refined linseed oil. You can add no more than 5% of dammar or Venice turpentine or rosin or Canada balsam to it to improve gloss and paint fluidity. I guess, Canada balsam is the best ever.
If you have a free aluminum tube, you can grind dried powder with oil again, using muller, and fill a tube with this finest oil paint.
You can add 1% of Bees wax solution in natural turpentine to prevent oil-pigment separation in tube. :thumbsup: And G. O'Hanlon can envy your paint! :D

Mythrill
06-04-2014, 08:15 PM
So, this is a hell of a lot of fun.
Now I have to find a source of green, blue, and white... that aren't highly toxic...

I really like cooking powders. Grinding them really well, cooking them for 750 degrees for 3-4 hours, then sifting them through a replaceable coffee filter into a jar produces a pigment that is ingredable fine, and with a bit of oil it mulls SO much more easily than the wet solution I've been working with with the umber I dug out of my back yard. I'm gonna try drying some of it out, but I doubt it'll work as well as grinding a rock down...

I still can't tell what's gonna happen when I cook different pigments. Usually they turn redder, some turn orange, some dark ones lighten up, some do nothing, one turned a very deep red with a violet base.

Before:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-bef.jpg

After:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-af.jpg

I also found a use for the silt that you filter out of pigment mixed in water:

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-IMG_7765.jpg

I've been trying to get the most out of my pigments as I can - I grind them super fine, sift them through a fine strainer, grind the stuff that didn't go through the sifter, sift again, put it in water, let it settle and pour the top off,

http://www.wetcanvas.com/Community/images/04-Jun-2014/1791740-IMG_7770.jpg

pour the silty heavy stuff that fell to the bottom into my mortar and grind it some more, pour it back into the jar of pigment and water... then filter the pigment by letting it separate and pouring off the top many times over several days.

This seems to give me the best success so far...
There are a few rocks though, that can just be ground up and sifted and are fine enough to be mulled right then and there. No idea what the difference is. :confused:

I've figured out that the best source of rocks around here seems to be areas around the river, right after rapids/falls but before the water slows down. The fast moving water seems to bring all sorts of rocks up, but by the time it turns into a slow river, there's just river rocks and mud.

I gotta go find some more places to look now!

Much thanks to Mythrill, Gigalot. You guys shared a lot of very useful knowledge with me, and now I can make an entire pallet of brick shades and umbers! :lol:

The biggest thing I have to figure out now is how to accurately prep pigments from their natural state to ready-to-mull... Clay is easy enough with the water settling method, and so are some of the pigments I've found around. But some of them (the nicest looking, of course - bright orangey-red naturally) when ground incredibly fine and mixed with water, eventually just seperate completely.

So there's just clear water on top, and the dust on the bottom. :/
I've had that happen with orangey-red rocks that broke apart easily, and with beige and light brown stones that required a bit of tapping with my pestle.

Not sure what to do there, as they're not ready to mull after grinding, but in water they just cleanly seperate. o.O

Any suggestions?

Ps. Sorry for the enormous run-on post!

Hi, Damien!

The pigments you got are very beautiful. :)

As for the insoluble pigments, you should filter the excess water and allow the rest to go away by evaporation. Then, just add oil to that pigment.

I think that should work.

Damienl
06-05-2014, 01:41 AM
Gigalot: Thanks for the tips! I'm still looking for a source for empty tubes locally (I'm in the capital city of my entire country, you'd think you'd be able to find anything here!)... I will try the real wax + turp mix when I do (Right now I'm just using cold wax medium).

Mythrill: I'm removing the water from the top of the "heavy" pigments, and patiently let them evaporate. While I get more rocks to keep me busy. :evil:

I ground up some Lapis Lazuli today - wow! That's a nice, strong blue!

http://www.wetcanvas.com/Community/images/05-Jun-2014/1791740-lapis1.jpg

http://www.wetcanvas.com/Community/images/05-Jun-2014/1791740-lapis2.jpg

I got it fairly smooth, it's a bit gritty but the "grit" is so small you can barely notice it.

On the bottom below the straight Lapis, on the left is the paint mixed 1:1 with titanium white (Strong pigment!), then to the right of that is the blue/white mix with a smidge of the cad lemon yellow that was still a bit wet mixed in.

I think I'll add something to make the mix more consistent - I've had good experiences adding a tiny bit of Gamblin's Cold Wax (a tiny bit, say 5% seems to do a lot).

This is fun. :D

Mythrill
06-05-2014, 01:30 PM
Gigalot: Thanks for the tips! I'm still looking for a source for empty tubes locally (I'm in the capital city of my entire country, you'd think you'd be able to find anything here!)... I will try the real wax + turp mix when I do (Right now I'm just using cold wax medium).

Mythrill: I'm removing the water from the top of the "heavy" pigments, and patiently let them evaporate. While I get more rocks to keep me busy. :evil:

I ground up some Lapis Lazuli today - wow! That's a nice, strong blue!

http://www.wetcanvas.com/Community/images/05-Jun-2014/1791740-lapis1.jpg

http://www.wetcanvas.com/Community/images/05-Jun-2014/1791740-lapis2.jpg

I got it fairly smooth, it's a bit gritty but the "grit" is so small you can barely notice it.

On the bottom below the straight Lapis, on the left is the paint mixed 1:1 with titanium white (Strong pigment!), then to the right of that is the blue/white mix with a smidge of the cad lemon yellow that was still a bit wet mixed in.

I think I'll add something to make the mix more consistent - I've had good experiences adding a tiny bit of Gamblin's Cold Wax (a tiny bit, say 5% seems to do a lot).

This is fun. :D

Say what? Lapis?

That's a very rare stone, and usually only found in Chile and Afghanistan! Did you buy your stone on the Internet?

Damienl
06-05-2014, 04:19 PM
Say what? Lapis?

That's a very rare stone, and usually only found in Chile and Afghanistan! Did you buy your stone on the Internet?

No, I cheated and bought a small imperfect piece at a lapidary.

Also, if you know what to look for you can often find old pieces of lapis from broken jewelry, necklaces, etc at antique stores (There are tons of them here) for cheaper than buying new pieces. It's a bit of a gamble for me though because there are a few copycat stones sold as lapis that I'm not good enough to tell the difference between yet.

Mythrill
06-05-2014, 08:58 PM
No, I cheated and bought a small imperfect piece at a lapidary.

Also, if you know what to look for you can often find old pieces of lapis from broken jewelry, necklaces, etc at antique stores (There are tons of them here) for cheaper than buying new pieces. It's a bit of a gamble for me though because there are a few copycat stones sold as lapis that I'm not good enough to tell the difference between yet.

Wow, Damien! For a small, imperfect piece, this looks great! You usually can get only a tiny bit of Lapis from a single stone, and you got a lot of pigment!

I can see the impurities that usually come with natural Lapis there, so I don't believe this is a fake stone. However, here's what it could be if you got a good imitation.

1. You got lots of cobalt and some glass – this would make instead an artificial Smalt pigment, all rare by itself.

2. You got artificial ultramarine mixed with the impurities that are usually mixed with Lapis – pyrite and calcite (possible.)

3. Another pigment mixed with some glass (unlikely.)

The cheapest imitations of Lapis are usually made of plastic resin and a dye like Phthalo Blue, so I doubt you would even have anything to grind if you got this type of imitation.

But, again, considering how your pigment seems to behave, I doubt that your Lapis' quality was that bad – maybe the jeweler consider it too dark?

You could get other flawed jewels and try that too. One that I know that certainly works is Turquoise. Daniel Smith has this one, and llwarence mentions it in his thread: http://www.wetcanvas.com/forums/showthread.php?t=1350130

indraneel
06-06-2014, 01:14 PM
Wonderful bottles of powder! I got lost in all that mulling, but did you all use a stainless steel mortar and pestle at any point? I recently pummeled some pumice (for pastels) in my marble mortar and it came out nice.

Gigalot
06-09-2014, 02:08 PM
"How much hand grinding is needed to form satisfactory pigment dispersions in drying oil vehicle? Moreover, how can you tell when sufficient grinding has been done? The answers to these questions are not simple to provide and depend upon the pigment and vehicle selected for hand grinding. However, I can provide some general guidelines that may help artists in this task:

When adding oil to the pile of dry powder pigment on the stone slab or glass plate, do so drop wise (drop-by-drop), mixing the oil with a spatula or palette knife, until all the pigment powder is incorporated and the mixture has a stiff, dough-like consistency. DO NOT ADD MORE OIL TO THE MIXTURE AT THIS POINT. The mixture will appear too stiff for painting, but this is all right, because the stiff mass creates more shear forces as it is kneaded and, as the pigment particles are wetted, it will relax and become more plastic.

Knead this mixture for some time with the spatula or palette knife, carefully observing changes in the consistency of the mass. For most pigments, you should observe a slight yet noticeable change from a stiff consistency to one that is softer and plastic. Continue kneading the mass, as the change in consistency indicates that agglomerates of pigment particles are breaking down into smaller ones and more pigment particle surfaces are being presented for wetting by the vehicle.

If you do not notice any further change in the consistency of the mass, stop kneading it with the spatula or palette knife. Some pigments, such as ultramarine blue or lapis lazuli (natural ultramarine blue), are refractory and difficult to grind to the right consistency. The best approach to grinding such pigments is to knead the mass until no further change is observed in its consistency and then allow the mixture to "sweat." Sweating is a paint maker's term for allowing the pigment-vehicle mixture to stand for a period. Cover the mixture with a plastic film and let it stand overnight. Some pigment agglomerates simply require time to allow the air in their interstices to escape and for the vehicle to wet their surfaces.

If the well-kneaded mass has the consistency of stiff yet plastic paste (somewhere between dough and toothpaste), then you are ready to begin grinding the mixture with a muller. If the mixture is too stiff for grinding with the muller, then add more vehicle drop-by-drop. Knead the mixture between drops of oil to check the consistency of the mass. It typically takes only a few drops to turn a stiff dough-like mass into a runny liquid so caution in adding more vehicle is necessary.

Stiff paste is the best word to describe the consistency of the pigment-vehicle mixture that is best suited for hand grinding with the muller. It should be slight more stiff than you would use for painting. It will become more fluid as you grind, so avoid the temptation to add more vehicle at this point.

Gather the mixture into a pile at the center of the slab or plate and begin grinding with the muller in circular motions. Some may advise that you grind in figure-eight motions or other fancy gyrations. It makes little difference as long as you grind all of the mixture thoroughly.

Periodically, using the spatula or palette knife, gather the mixture back together at the center as you spread it around on the slab or plate when grinding.

As you grind the mixture, you will notice a distinct change in the consistency of the paint:
At first, pigment agglomerates will make small tracks in the mixture as you grind. You will see these begin to disappear entirely or at least become fewer in number. They may never disappear entirely, even if you grind from now until you wear a hole in the plate. Do not worry; you may never completely rid yourself of them and in themselves do not indicate a poor dispersion, because some may be large discrete particles of pigment and do not ruin the paint or decrease its brushability.

Initially, the paint should have a stiff paste-like consistency. As you grind with the muller, the paint will become more plastic and flowing. If it becomes runny and liquid, then you may have added too much oil. No problem, because you can add more pigment to the mixture. The only problem with adding more pigment at this stage is that it will increase the time needed to grind the paint.

The paint will usually have a dull mat surface before you grind. As the grinding proceeds, the surface of the paint will become glossy when you stop grinding and it is allowed to rest. This indicates that pigment particles are being wetted and are "sinking in" to the vehicle.

There will be a distinct change in the sounds emanating from the grinding. It may initially sound like sand grinding on the plate surface and then soften and become more quite. This alone does not indicate that the paint mass has been sufficiently ground and a good dispersion has been achieved. The reason is quite simple; some pigments never cause the sound of sand grinding while others never quite stop making this sound. It all depends on the hardness of the pigment being ground. Some mineral pigments are very hard, such as azurite, malachite and earth pigments containing a small amount of silica (sand). In any case, a distinct change in the sound should be noticed while you are grinding with the muller.

If after grinding for some time the consistency of the paint does not soften to the viscosity that you prefer for painting, then add more vehicle, but do so drop wise and check the consistency after every one or two drops.

After observing the four characteristics noted above while grinding and you do not notice further changes in them, you most likely have achieved the best dispersion possible with hand grinding. You can congratulate yourself for hard work accomplished."
G.O'Hanlon

Mythrill
06-10-2014, 04:17 PM
Damien, it's been a while. How's your painting going?

Damienl
06-11-2014, 11:24 AM
Wow, Damien! For a small, imperfect piece, this looks great! You usually can get only a tiny bit of Lapis from a single stone, and you got a lot of pigment!

I can see the impurities that usually come with natural Lapis there, so I don't believe this is a fake stone. However, here's what it could be if you got a good imitation.

1. You got lots of cobalt and some glass – this would make instead an artificial Smalt pigment, all rare by itself.

2. You got artificial ultramarine mixed with the impurities that are usually mixed with Lapis – pyrite and calcite (possible.)

3. Another pigment mixed with some glass (unlikely.)

The cheapest imitations of Lapis are usually made of plastic resin and a dye like Phthalo Blue, so I doubt you would even have anything to grind if you got this type of imitation.

But, again, considering how your pigment seems to behave, I doubt that your Lapis' quality was that bad – maybe the jeweler consider it too dark?

You could get other flawed jewels and try that too. One that I know that certainly works is Turquoise. Daniel Smith has this one, and llwarence mentions it in his thread: http://www.wetcanvas.com/forums/showthread.php?t=1350130

The stone was actually pretty dark blue - I picked it for that reason. If I decide to make more, a good friend of mine is an apprentice goldsmith and works in an independent jewelry store, so I'm gonna see if he can hook me up with some good (and cheap) lapis for my purposes!

I have tried some experiments - found a few pigments that were way too gritty and I couldn't grind them down fine enough, not sure what they were.
I have a whole bunch of umber waiting to dry out - one batch turned out with much more of a green tinge than the other.

I have a HUGE lead primed canvas I stretched - I forget how big it is, but it's almost as tall as I am - and I think it would be cool to use my own paint on it!

And hopefully by the time the canvas is ready and I'm confident enough in my paint, I won't suck at painting. :lol:

In completely unrelated news, I also found a cool box to put all my little bottles in (I'm a bit obsessive with having cool containers), and the coolest box for my paints. It was really, really grungy and beat up, bought it for $5.99. Refinishing, new hardware, bit of woodworking, and super cheesy lionhead pulls on top. Haha
Looking for the appropriate place to post this on here, but until then:

http://www.wetcanvas.com/Community/images/11-Jun-2014/1791740-box.jpg

Damienl
06-11-2014, 04:58 PM
The "Pretty rock that was prettier than all the other rocks" was finally done my wacky filtering process today. I broke it up back into powder, added some oil, and it practically didn't need to be mulled at all! I think I did 5-10 minutes of mulling, with the last 5 minutes just making sure it was actually done.
I haven't seen one of these rocks since, and I didn't get much paint out of it. :(

http://www.wetcanvas.com/Community/images/11-Jun-2014/1791740-p2.jpg

So I've gone through 15-20 different rocks and things, ground and mulled and experimented....And these are the only three paints I've made that are successful. :lol:

Left to right is the pretty rock that I don't know what it is, the umbery stuff I dug out of a 4' hole in my backyard, and the Lapis I bought and ground up.

http://www.wetcanvas.com/Community/images/11-Jun-2014/1791740-p1.jpg

Mythrill
06-11-2014, 05:31 PM
The "Pretty rock that was prettier than all the other rocks" was finally done my wacky filtering process today. I broke it up back into powder, added some oil, and it practically didn't need to be mulled at all! I think I did 5-10 minutes of mulling, with the last 5 minutes just making sure it was actually done.
I haven't seen one of these rocks since, and I didn't get much paint out of it. :(

http://www.wetcanvas.com/Community/images/11-Jun-2014/1791740-p2.jpg

So I've gone through 15-20 different rocks and things, ground and mulled and experimented....And these are the only three paints I've made that are successful. :lol:

Left to right is the pretty rock that I don't know what it is, the umbery stuff I dug out of a 4' hole in my backyard, and the Lapis I bought and ground up.

http://www.wetcanvas.com/Community/images/11-Jun-2014/1791740-p1.jpg

Damien, first of all... wow! You got a lot of paint!

The pretty rock that you have there gave you what seems like Red Ochre (PR 102.) I can't call it "Burnt Sienna" (PBr 7) because even though it's exactly around the same hue (but more opaque than the "historical" one) you did say you get it by crushing a rock, and it you didn't say it went through burning.

It's certainly very beautiful, but don't despair! If you never find any rock like that again, the yellow-orange ochre you burnt will give you some nice oranges just around this shade – if not a bit lighter and cleaner!