PDA

View Full Version : What does "Permanance" mean?


willemo
12-08-2010, 10:04 AM
My oil paint tubes all have a "permanence" rating (i.e. 3 stars).

Is permanence the same the same as opacity? Or am I confused?

mickeyw3340
12-08-2010, 11:48 AM
Permanence is the rating for longevity. Sunlight is a cuilprit for all artists paint. If you are painting as a hobby, not a big issue. If you want your paintings to be appraised for thousands of dollars 100 years from now on "Antique Road Show" then use highest rated permanence in your paints.

Einion
12-08-2010, 02:16 PM
Permanence in paints is basically a combination of lightfastness - fading (or other discolouration) due to light exposure - as well as other ageing characteristics, including colour changes that may be due to chemical reasons.

However it can be used by some paintmakers simply to mean lightfastness.

Einion

willemo
12-09-2010, 02:32 AM
Very interesting. I didn't think about paints fading over time, but I guess it makes perfect sense.

Thanks :)

Gigalot
12-09-2010, 01:41 PM
Most of average lightfastness paints are 20-30 times more permanent in masstone than in tints.
Because of this for the high tints I always use light resistant pigments, but i guess most of paints are good enough in masstone.

Alex

Einion
12-09-2010, 05:03 PM
I didn't think about paints fading over time, but I guess it makes perfect sense.
It used to be more common (more than it really should have been) but it's thankfully relatively rare now.

These days the only commonplace pigment that's fugitive is Alizarin Crimson, which especially in watercolour can exhibit pronounced fading.

Einion

sparkling
12-31-2010, 09:40 AM
These days the only commonplace pigment that's fugitive is Alizarin Crimson, which especially in watercolour can exhibit pronounced fading.

Einion, I've noticed that a couple of brands (like W&N) sell a Permanent Alizarin Crimson. Is this one still fugitive or is it made of different pigment(s) that will last longer?

jumpforjoy61
12-31-2010, 05:12 PM
Einion, I've noticed that a couple of brands (like W&N) sell a Permanent Alizarin Crimson. Is this one still fugitive or is it made of different pigment(s) that will last longer?

permanent didn't actualy mean light fast when some of these pigments where first manufactured ,in fact some "permanent" colours where in fact some of the more fugent ones
although i cant say for sure it may well be that W&N have used the original description for that pigment so don't get fooled by the word permanent if it just a part of the name for the colour and not a separate description of the pigments performance

i much prefer the industry recognised BWS ratings over these manufacturers 3 star ratings

also lightfastness can be dramaticaly reduced at tinting levels so dont take anything for granted especialy as most manufacturers dont actualy do any lightfastness testing anyway;)
Paul

sparkling
01-01-2011, 06:17 AM
Oh wow, that's not good. :(
I'll guess I'll better have to remove every Alizarin Crimson I so far have. Just got a set of W&N Artists Acrylics for X-mas which comes with a Perm. Aliz., but I guess I'll need to get myself another red now. Speaking of which, do any of you have suggestions for good substitutes?

oddman99
01-01-2011, 08:52 AM
Permanent Alizarin is actually a good substitute, at least as far as lightfastness goes. That was why it was formulated.

jumpforjoy61
01-01-2011, 12:09 PM
Oh wow, that's not good. :(
I'll guess I'll better have to remove every Alizarin Crimson I so far have. Just got a set of W&N Artists Acrylics for X-mas which comes with a Perm. Aliz., but I guess I'll need to get myself another red now. Speaking of which, do any of you have suggestions for good substitutes?

well as i said i wasnt sure regarding the W&N version it may well be a lightfast version however what you realy need to do is check with the manufacturer

all i am saying is permanant does not automaticly mean lightfast hence it isn't the most usefull term as it can be misleading.
If only manufacturers would state industry recognised ratings rather than making up thier own ,basicly most of them dont want us to know how bad some of thier products can actualy be in this respect

take thermochromatic pigments ,some companies like Alsa sell this type of stuff for custom painting and they dont sell it cheaply either ,yet it is rarely over 1 BWS and will often fade out in days to weeks

W&N actualy seem to be amongst the best for lightfastness,but for the artist the only sure way to find out is to run your own BWS tests which is actualy very simple
Paul

jumpforjoy61
01-01-2011, 12:22 PM
quoted from handprint site

"
outdated labeling conventions peculiar to the art materials market (spectrum yellow, primary yellow or permanent yellow). "Permanent" is especially misleading: it was originally a 19th century paint marketing label that meant "a synthetic organic pigment that is not derived from aniline (http://www.handprint.com/HP/WCL/pigmt1d.html)"; it has never meant "a paint that won't fade".

Einion
01-04-2011, 04:35 PM
Einion, I've noticed that a couple of brands (like W&N) sell a Permanent Alizarin Crimson. Is this one still fugitive or is it made of different pigment(s) that will last longer?
The W&N paints of this name are not fugitive, no.

In watercolour their version is made from PR206 (Quinacridone Maroon), in oil paint it's made from PR177 (Anthraquinone Red) and in acrylic it's made from PR177 blended with Dioxazine Purple. All three can be considered lightfast, although just how lightfast varies a little.

Speaking of which, do any of you have suggestions for good substitutes?
There are actually a number of prior threads that feature discussion on suitable substitutes or alternatives; unfortunately it's not as simple as "Use XXXX" because no alternatives are exactly like the real thing and how important this is varies from painter to painter, a lot :D

In addition to the crimson-coloured paints like PR177 and PR264 that are worth consideration as direct substitutes for Ali Crimson you can structure the palette differently, for example skipping over this colour and going for something more toward violet like Quinacridone Rose or Quinacridone Magenta.

Einion

Gigalot
01-04-2011, 04:40 PM
My own oil paints lightfastness test on my balcony during 2 year with 1:5 paint/white PW6 on white plastic plate show me that:

1. Lemon yellow PY3 and orange PO13 lost its initial color absolutely and became white.
2. Phthalo Green PG7 and PR146+PB29 (naphthol carmine FBB & UMB) lost about`50% it`s initial color.
3 Cad yellow deep PY37, Prussian Blue PB27, Cobalt Violet light PV14 and Quinacridone Magenta PR122 are all about the same as it`s initial color.

Therefore, if "Permanent Alizarin" means one or more Quinacridone pigments like PR122, PR209, PV19 you can use it without any trouble! This organic pigments have "mineral pigments" permanency and even more lightfast than phthalo green!

Prussian blue PB27 are surprisingly light and weather fast on plastic surface.

Einion
01-05-2011, 08:04 AM
It's not quite as simple as that Alex. While our own lightfastness testing is something anyone concerned with the permanence of their materials should do, we can't extrapolate too much from the results. This is especially true if the testing conditions are unique or non-standard but equally as important is that pigment performance commonly varies depending on the version - PR122 for example would regularly test noticeably below the lightfastness of Phthalo Green BS (still very lightfast normally, but not quite to the same level as PG7, which is absolutely lightfast).

As another example of variation, in my own test of PY3 in acrylics it performed much better than in yours - after two years of continual southern exposure I couldn't detect any change. In watercolour this pigment is rated ASTM II but it does show a wide range of performance and yours would appear to be one that's not as good as this pigment can be at best.

Einion

jumpforjoy61
01-05-2011, 10:37 AM
not too long ago Createx had an issue with thier new range of airbrush colours IE Wicked Colors ,thier chemist went out of his way to provide lightfast pigmented inks with only a couple being less than 8 BWS .the trouble arose with orange #7 pigment which although lightast in its own right when mixed with white at tinting levels it faded out dramaticly ,it wasnt untill users started to report back that the problem was discovered and the pigment was withdrawn and replaced with another

my point here being that even after lightfast testing under one set of circumstances we may not be 100% certain the same results will always hold true under another set of circumstances

Paul