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View Full Version : Asphaltum (Bitumen). Is it ASTM tested?


Gigalot
05-01-2010, 06:11 PM
Most of the paintings that use asphaltum was seriously affected by its melting point. But some artists like Bouguereau are very well used it`s thin layers. I haven`t found anywhere information about its lightfastness. Is this light-resistant material?

llawrence
05-01-2010, 10:56 PM
According to naturalpigments.com, asphaltum is not rated by ASTM. I don't know if it's considered lightfast or not.

Rose Queen
05-01-2010, 11:12 PM
I find the ASTM website pretty clunky to use, but all I found searching keywords 'asphaltum' and 'bitumen' had to do with its use as an adhesive or paving material, so I think llawrence is correct.

sidbledsoe
05-02-2010, 09:58 AM
Here (http://www.artiscreation.com/brown.html) it is given a III rating, or poor. It is the first pigment listed on this page in this reference site.
This is the bitumen pigment, most makers like Gamblin, Mussini, make a hue color called asphaltum but they are made with lightfast pigments like iron oxides and earths.

llawrence
05-02-2010, 11:56 AM
Yeah, seems like it's pretty well replaced with transparent iron oxides - unless one is really into trying out the original (which I understand). But from what I've read it was mostly a disaster and unworkable for most artists.

Gigalot
05-02-2010, 01:05 PM
Very interesting:

"A transparent brown to black-brown mineral pigment used in tempera, oil and watercolor mediums, obtained from natural asphaltum deposits in Utah.

Gilsonite, or North American Asphaltum is a natural, resinous hydrocarbon found in the Uintah Basin in northeastern Utah. It is brittle and can be easily crushed into a dark brown powder".

And an Utah Asphaltum has a high melting temperature! :)

llawrence
05-03-2010, 12:44 PM
Gigalot, if you wind up testing the Utah asphaltum, please let us know how it works out!

Gigalot
05-03-2010, 04:39 PM
To go to Utah from Georgia for the asphaltum only! Cool!
One picture I would have to paint entirely with bitumen, if I would live out there. Is anybody from Utah here?

rcollege
05-12-2010, 05:18 AM
Bear in mind that many oil paintings have been retouched throughout their life...so what seems to have held up may have not and required new paint as a retouch.
Earth Pigments has an Envirox brown I'm looking into...it is iron oxide collected from the sludge produced during iron production. Pretty dark...but I'll have to make it again as I sent the paint out as a sample.

Einion
05-12-2010, 08:10 AM
Bear in mind that many oil paintings have been retouched throughout their life...so what seems to have held up may have not and required new paint as a retouch.
Yep, important to bear this in mind. I made the same point in a previous thread about Alizarin Crimson/madder lakes, that without knowing for sure what's retouched and what's not one can't just assume that good reds in old paintings (where it's pretty clear from the colour that there's some crimson mixed in, or used as a glaze) are proof that used a certain way they have stood up to centuries of light exposure.

Einion

rcollege
05-14-2010, 11:32 AM
Yes, this become inavoidably evident while I walked through a museum and the third time I walked through all the older (1600's - 1700's) oil painting were noticably brighter, newer and smoother than before with reds and yellows really popping out. The colors could have been from new lighting...but even my wife was noticing how smoothed over the figures and skin tones looked...and how intense as well as subtle the reds and yellows had become.

Gigalot
05-14-2010, 01:25 PM
Argue that in this Vermeer`s painting Alizarin is well preserved. But I have not seen the data of expert examination.

rcollege
05-14-2010, 07:04 PM
My apologies for any confusion...I was replying in agreement to Einion.
I know little about what palettes certain artists used...and Vermeer is one artist that I know very little about.
I'm not sure what restoration has taken place with this piece. Another question is if he had used vermilion in this painting, as vermilion was often covered by alizarin crimson. How has it been stored? How long has it been displayed? Again, I'm not remotely close to an authority on artists...I do know alizarin is not permanent in the presence of continuous light...there are manuscripts however where organic pigments have lasted.

You know...now that I'm looking at this on my monitor( so my colors may be off)...I wonder if the dress is truly alizarin, or if it is a venetian red coated with alizarin.

Oh well...I guess I have more research to do...I could almost get this color from a venetian red in watercolor...with a touch of ercolano or vermilion.

llawrence
05-15-2010, 12:31 AM
From what I understand it is vermilion glazed with madder.

According to George O'Hanlon (sorry to keep quoting the same source), there are some unrestored examples of lake pigments used historically that for some reason have performed way better than testing indicates they should - Vermeer's Girl with the Red Hat I think was the example he gave - but that so far there has not been any real research to discover why. If I ever happen to get rich that's one area that will get some funding!

Termini.
05-23-2010, 03:02 AM
From what I understand it is vermilion glazed with madder.

According to George O'Hanlon (sorry to keep quoting the same source), there are some unrestored examples of lake pigments used historically that for some reason have performed way better than testing indicates they should - Vermeer's Girl with the Red Hat I think was the example he gave - but that so far there has not been any real research to discover why. If I ever happen to get rich that's one area that will get some funding!

The Winsor and Newton Natural rose madder performs very well, so obviously it can be manufactured in a manner that is lightfast.

Termini.
05-23-2010, 03:27 AM
Most of the paintings that use asphaltum was seriously affected by its melting point. But some artists like Bouguereau are very well used it`s thin layers. I haven`t found anywhere information about its lightfastness. Is this light-resistant material?

The problem with this material is that it was not a pigment, but rather a tar substance that was thinned down, and placed over an oil film. It dries very slowly, and many types will bleach out due to oxidation and light.

Bituminous material occurs naturally all over the world. Not all is the same, no more than all crude oil is the same (sour/sweet). Therefore, we don't know specifically what type and which sources were used by those who were able to use it sucessfully. Hypothetically, an artist from the past could have obtained some of this material that could be used sucessfully, and done so. Then this becomes documented: i.e. that the particular artist used asphaltum. Because of this, present day artists could go get some bituminous material from an entirely different source, that produces dismal results. Confusion would then result, and everyone would be asking what it was that the old masters did, in order to use this properly. In order to know how Bouguereau use this, one would need to have either read specific notes left by him, or watched him make it. We also don't know whether or not he combined it with a medium. He used a hard resin medium which was combined with gum elemi, in his paint, and who knows if he also used this with the asphaltum? There appear to be too many unknowns.


I wouldn't chance putting any asphaltum on any of my paintings. As Sid said, there are hues. I have piles of Gamblin asphaltum hue. I would mention that Rembrandt makes a decent asphaltum hue, that comes very close to the actual, in my opinion, if a little WN Indian yellow is added. With the number of lightfast, well made and stable materials presently available, I don't need the actual material.

llawrence
05-23-2010, 12:47 PM
The Winsor and Newton Natural rose madder performs very well, so obviously it can be manufactured in a manner that is lightfast.You've tested it? I want to do some tests this year and, among other things, test WN's rose madder against my own madder lake and see how they do. Just waiting for the sunshine, should start any old month now... :( :cool:

I adore madder lake over all other colors, here's hoping it performs as well as you say.

Termini.
05-23-2010, 11:50 PM
You've tested it? I want to do some tests this year and, among other things, test WN's rose madder against my own madder lake and see how they do. Just waiting for the sunshine, should start any old month now... :( :cool:

I adore madder lake over all other colors, here's hoping it performs as well as you say.


I have tested WN Rose Madder deep, against quite a few others (alizarin/perm.aliz etc.), and it does perform well. I don't know about the new version, as the Rose madder deep isn't being offered any more, Perhaps the natural rose madder is the same, and it does have the same pigment number. I found an old tube in a discount bin of an art supply store for $3.00, just before they went out of business about 10 years ago. I recently found an old tube in another art supply store, but they wanted $54.00, and I don't think I will ever be able to get use to paying that much for a small tube of paint on a regular basis, so I passed it by. My tests were not extensive, and if you are interested in more in depth information, you may want to ask Virgil Elliott. He has done quite a bit of testing on this, and is very knowledgeable. It is my understanding that WN is the only manufacturer who is able to produce this color in a light fast version. How ever they do it, they are good. I also love this color.

Virgil Elliott
05-24-2010, 12:43 AM
I'll touch on several points raised in this discussion:

The asphaltum used in centuries-old oil paintings is a problematic substance for painting in oils, not because it isn't lightfast, but because it has no solid substance to it, and is thus subject to excessive shrinkage, which leads to cracking.

There is no alizarin crimson in any painting done by Vermeer. It did not exist in Vermeer's time. What was available then in the way of transparent reds of more or less similar hue were madder lake and carmine, aka cochineal.

Winsor & Newton's Rose Madder Deep, in my own lightfastness tests, performed well in masstone, and mixed 50/50 with white it faded less than alizarin crimson mixed with the same white in the same percentage. Unfortunately, Rose Madder Deep has been discontinued, but Rose Madder Genuine is still available from W&N, and its lightfastness is only very slightly lower than Rose Madder Deep, but still significantly better than alizarin crimson, according to my tests.

Virgil Elliott

Virgil Elliott
05-24-2010, 12:59 AM
A good substitute for asphaltum can be mixed from transparent oxide red and a small percentage of phthalocyanine green or phthalocyanine blue. By varying the proportions of these pigments in the mixtures, a full range of dark transparent browns can be made that can take the place of the problematic dark browns used by painters of centuries past, including bitumen, Cassel earth, Van Dyck Brown, mummy, as well as asphaltum. These approximations should endure centuries in much better condition than the older pigments.

Virgil Elliott

llawrence
05-24-2010, 12:21 PM
Thank you Termini and Virgil for the information. I'll post the results of this year's tests once they finally happen.

Gigalot
05-25-2010, 05:07 AM
This is a good example of misuse of the material has become almost legendary. Known a lot of other examples of damage to paintings from the immoderate use of varnishes, adhesive soil of white lead mixed with sulfur and organic matter, deterioration of the paint layer of shellac, improper drying, etc. But especially well remembered for melting bitumen, and this despite the fact that in chemistry there are many ways to it`s polymerization. Adding to the bitumen alkyd varnish and drying oils removes this problem completely.

Termini.
05-26-2010, 01:27 AM
This is a good example of misuse of the material has become almost legendary. Known a lot of other examples of damage to paintings from the immoderate use of varnishes, adhesive soil of white lead mixed with sulfur and organic matter, deterioration of the paint layer of shellac, improper drying, etc. But especially well remembered for melting bitumen, and this despite the fact that in chemistry there are many ways to it`s polymerization. Adding to the bitumen alkyd varnish and drying oils removes this problem completely.

Well, masters of bygone eras certainly didn't have alkyd resins. There certainly is enough evidence that asphaltum has caused many problems in oil painting. It is a shame because the material I have seen is beautiful, but I simply won't chance using this stuff.

Einion
05-26-2010, 02:48 AM
Bituminous material occurs naturally all over the world. Not all is the same, no more than all crude oil is the same (sour/sweet). Therefore, we don't know specifically what type and which sources were used by those who were able to use it sucessfully. Hypothetically, an artist from the past could have obtained some of this material that could be used sucessfully, and done so. Then this becomes documented: i.e. that the particular artist used asphaltum. Because of this, present day artists could go get some bituminous material from an entirely different source, that produces dismal results.
Excellent point, very similar to the issue with the use of copal or 'copal'.

In addition to the variability of the stuff itself, and then how it was treated within the painting method, very small amounts (thin layers and/or being added in small amounts to mixtures) v. being used excessively (thick layers, with or without varnish; used as a major component in mixtures) can't be overlooked. Irrespective of this, your closing point below is the take-home message IMO.

I wouldn't chance putting any asphaltum on any of my paintings. ...With the number of lightfast, well made and stable materials presently available, I don't need the actual material.
http://www.wetcanvas.com/Community/images/20-Aug-2003/3842-thumbsup.gif


Winsor & Newton's Rose Madder Deep, in my own lightfastness tests, performed well in masstone, and mixed 50/50 with white it faded less than alizarin crimson mixed with the same white in the same percentage. Unfortunately, Rose Madder Deep has been discontinued, but Rose Madder Genuine is still available from W&N, and its lightfastness is only very slightly lower than Rose Madder Deep, but still significantly better than alizarin crimson, according to my tests.
But still not good enough to use for permanent work IYO?

Approximately what ASTM lightfastness rating would it have? Or Blue-Wool Scale if you have that.

A good substitute for asphaltum can be mixed from transparent oxide red and a small percentage of phthalocyanine green or phthalocyanine blue. By varying the proportions of these pigments in the mixtures, a full range of dark transparent browns can be made that can take the place of the problematic dark browns used by painters of centuries past, including bitumen, Cassel earth, Van Dyck Brown, mummy, as well as asphaltum. These approximations should endure centuries in much better condition than the older pigments.
Thanks for that - this is exactly the kind of common-sense replacements that I think we (painters of today) should be focussing on.


But especially well remembered for melting bitumen, and this despite the fact that in chemistry there are many ways to it`s polymerization. Adding to the bitumen alkyd varnish and drying oils removes this problem completely.
But the material itself is inherently problematic; knowing better ways of utilising it doesn't actually make it safe to use (assuming a goal of permanence; if there isn't one then it's not an issue obviously).

Einion

Gigalot
05-26-2010, 07:06 AM
I concluded that knowledge of the problems that arise when using soft asphaltum in oil painting can help when working with other materials.

I found two major problems there:

1. Melting or softening of the layer of asphaltum that leads to sloughing and cracking of the upper layer.
2. Diffusion of asphaltum completely through the top layers that lie changes it`s color.

To physically prevent cracking layer of matter lying on top should be flexible layer underneath. If a solid layer lies over soft it will inevitably crack. This is what we often see in varnishing paintings with brittle resins. (not "fat over thin" but flex over hard:) )

The diffusion has many organic dyes (PY3 for exsample) and not just asphaltum. It is possible that many people will agree with me that if you want to apply this paint it must be on top of all other colors. Of course, it will penetrate into the layer under it but it does not hurt the overall color. But if this paint will be below the upper layer after time it will change color.

So you can use asphaltum with 30% - 50% alkyd on top layer without any trouble but only.
And it is safe to use acrylic over completely dried (after about 2 years) oil paint but it is really dangerous if acrylic underpainting for oil is very soft and thick.

Virgil Elliott
05-27-2010, 03:16 AM
But still not good enough to use for permanent work IYO?

Approximately what ASTM lightfastness rating would it have? Or Blue-Wool Scale if you have that.


Einion,

Winsor & Newton's Rose Madder Deep (discontinued) and Rose Madder Genuine are ASTM Lightfastness II, which is generally regarded as acceptable for fine art. I would use it in masstone (I have in the past) but not in mixtures with white, now that there are more lightfast alternatives available.

Virgil

Termini.
05-27-2010, 10:40 AM
Excellent point, very similar to the issue with the use of copal or 'copal'.

In addition to the variability of the stuff itself, and then how it was treated within the painting method, very small amounts (thin layers and/or being added in small amounts to mixtures) v. being used excessively (thick layers, with or without varnish; used as a major component in mixtures) can't be overlooked. Irrespective of this, your closing point below is the take-home message IMO.



Einion,

Thanks. I agree for the most regarding copal. Especially when I see much of what is being offered today.

Termini.
05-27-2010, 10:41 AM
Einion,

Winsor & Newton's Rose Madder Deep (discontinued) and Rose Madder Genuine are ASTM Lightfastness II, which is generally regarded as acceptable for fine art. I would use it in masstone (I have in the past) but not in mixtures with white, now that there are more lightfast alternatives available.

Virgil

Virgil,

Thank you very much for your experience on this matter.

Gigalot
05-27-2010, 02:26 PM
Expensive good solid fossil copal and amber unfortunately do not have a decent replacement for soft natural resins.

Instead of it we can try Alkyd Varnish.

Einion
05-27-2010, 02:30 PM
Thanks Virgil, that'll be useful for anyone who has it or would like to try it that is concerned with permanence.

Einion

llawrence
05-27-2010, 02:58 PM
I've perused part of a site whose author believes he has discovered (of course) a medium used by Rubens specifically to tame asphaltum and make oil paint dry a lot quicker. In general I ignore all "lost secrets of the old masters"™ claims for the sake of my own sanity (too many different secrets! Some of them must be wrong…) - but I figured I'd post the links and a pic of his work using the stuff, since they're relevant to this discussion, and see if anyone here has a differing opinion. He is selling his "fir wax" medium, so of course he's pushing it. He does at least seem to have found a way to make the asphaltum dry quickly enough to use in an underpainting - who knows what will happen to it in the long run. Gigalot, he is using exactly the asphaltum from Utah that you mentioned, which he calls gilsonite.

http://www.jamescgroves.com/firjelly.htm
http://www.jamescgroves.com/firwax.htm

http://www.wetcanvas.com/Community/images/27-May-2010/132386-firjelly20opt.jpg

That cliff looks nice and glowing - no question it's an alluring color for transparent passages. I wonder if the same effect could be at least partly achieved using a combination of the transparent iron oxides, but of course those were not always available.

Virgil Elliott
05-28-2010, 03:20 AM
I've perused part of a site whose author believes he has discovered (of course) a medium used by Rubens specifically to tame asphaltum and make oil paint dry a lot quicker. In general I ignore all "lost secrets of the old masters"™ claims for the sake of my own sanity (too many different secrets! Some of them must be wrong…) - but I figured I'd post the links and a pic of his work using the stuff, since they're relevant to this discussion, and see if anyone here has a differing opinion. He is selling his "fir wax" medium, so of course he's pushing it. He does at least seem to have found a way to make the asphaltum dry quickly enough to use in an underpainting - who knows what will happen to it in the long run. Gigalot, he is using exactly the asphaltum from Utah that you mentioned, which he calls gilsonite.

http://www.jamescgroves.com/firjelly.htm
http://www.jamescgroves.com/firwax.htm

http://www.wetcanvas.com/Community/images/27-May-2010/132386-firjelly20opt.jpg

That cliff looks nice and glowing - no question it's an alluring color for transparent passages. I wonder if the same effect could be at least partly achieved using a combination of the transparent iron oxides, but of course those were not always available.

Using asphaltum in an underpainting is asking for trouble, no matter how fast it dries, because it is not solid enough to provide stable support to any paint applied over it. Its traditional use was as a final deepening glaze for the darker darks, and even limited to that purpose it was problematic. The same optical effects are obtainable with the mixture I mentioned previously plus a bit of a transparentizing medium.

Virgil Elliott

Gigalot
05-28-2010, 05:41 AM
Thank you, Llawrence for such an interesting information!

Paintings are really beautiful and we can see that asphaltum reach beautiful translucent brown. We know that Boguereau has an iron oxides and Cassel Earth but despite this he used asphaltum that is the most transparent brown.

And I absolutely agree with respected and reputable Virgil Elliott that asphaltum is not for Underpainting! It is dangerous even for such enthusiasts like us. Paints contain a lot of oil that gradually shifts into the upper layers of asphaltum. The painting may be damaged during a few years.

Underpainting is not so important and it is better to make it with other safe colors.

The wax is soft and the properties of asphaltum will not improve.

We can add a lot of Tung Oil there, and dry in the sunlight for 2 days. After that, the asphaltum become hard enught but propensity to migrate is not reduced. It should also to cover this asphaltum on top with a thin film that does not pass oil. It is quite possible but you can agree too hard to do that.

Alex

Gigalot
05-30-2010, 08:09 AM
This is cracks in the thick layer of asphaltum ..