Your Oil Paints Will Fade - Learn Why and What You Can Do About It

[@herbsmith21]

Extremely informative and thanks for posting!!

[@virgilelliott]

I'm sorry I couldn't be there when this was live. I had a medical appointment at the time. Tatiana, I haven't ever tested Prussian blue, by the way. It's not a blue I ever saw a need for in any of my own paintings.

[@Divertedflight]

That straight lead white without zinc test on Prussian blue was a shock. Fortunately I've never trusted that colour despite the ASTM 1 rating. Regarding the ASTM, I think there needs to be the split in the ASTM 1's. Those colours that don't change at all, and those that change just a little. As I type this perhaps ASTM 0 ? Zero for effectively no change at all within human eye measurement. Though I could see some resistance for this within paint producers. A number of artists will only want to use the most permanent pigments and the fear could be logically made that the spread of sales across their ranges would decrease. On the other hand Winsor & Newton effectively already do this with the AA and A designations with what I imagine little evil effect.

[@MarinaMichaels]

You might be surprised at how many famous watercolor artists don't give a hoot about whether their paints, and therefore their paintings, are fugitive. They have their favorites and they don't care whether those paints are lightfast and permanent. I've taken classes from a few locally famous artists who recommended paints using fugitive pigments, knowing the pigments were fugitive. And some artists are too confused by pigments, so they ignore the issue entirely. Some of the people who've been doing their own independent lightfastness testing have, in their naivety, politely contacted famous artists alerting them to the fugitive qualities of their paints and asking them what they, the artist, is doing about it, only to be ignored.

[@Divertedflight]

@@MarinaMichaels An old problem. Upon William Winsor telling the famous painter not to use certain colours. Turner replied: Your business, Winsor, is to make colours. Mine is to use them."

[@RublevColours]

ASTM standard has 8 categories of lightfastness, but only categories i and II are acceptable as part of the oil paint standard, ASTM D4302.

[@masteroilpainting]

I love that you are testing pigments and sharing the results with us! Thank you. Hopefully, the Quins and the Phthalos will be tested soon since they are some of the more popular pigments individually and are also used for many hue colors like Manganese. I've not seen many artists using Prussian compared with Phthalo - do you sell a lot of Prussian compared with other pigments? Would it not be useful to test the more popular colors first? Maybe I'm way off and Prussian is used more than Phthalo. Also, is the Alizarin the historically fugitive pigment, or one of the newer 'permanent' hues?

[@RublevColours]

We sell a lot of Prussian blue. Alaizrin is also somewhat fugitive. The so-called permanent alizarin is not really alizarin at all and only somewhat resembles it.

[@vittoriobeghelli3561]

Very useful. Thank you!

[@RublevColours]

You're weclome!

[@malreigh]

Thank you for doing this :)

[@RublevColours]

Of course!

[@Algabatz]

Thank you, very informative as usual. I was thinking about the 40-year old tests made indoors and was wondering if there have been any tests made in LED-light. The museums may have incandescent lighting today, but here in Sweden they are getting increasingly hard to even come by.

[@RublevColours]

The international standard for testing the lightfastness of artist colors was established in the 1980s in cooperation with the American Society of Testing Materials (ASTM). The standards use two sources of lighting: Xenon arc lamps and sunlight. This is an accelerated test that is very harsh.

[@Algabatz]

@@RublevColours I see, then LED would practically have no effect. Thanks! Btw, I was very happy to find your European store a couple of months back. I have already bought a whole range of 20 Rublev paint tubes. I really love them. Thank you from Tony in Sweden!

[@RublevColours]

@@Algabatz@Algabatz Tony, LED lights will have an effect on the properties of pigments, but this depends on the spectrum of light and the total amount of radiation. ASTM uses Xenon lamps, and sunlight because these are standard methods used for many other products. Thank you for your patronage.

[@chrisgriffith1573]

I would think that your anomalies have some chemical reactions with the pigment compositions they are inside- such as the additives in titanium white (or the titanium itself) are affecting and coupling/uncoupling with what is in the Prussian Blue to allow the fading. Like you stated, more extensive testing is needed, a control for this can be done by mixing titanium with other pigments which have certain similar compositions vs those that do not... once you identify a marker for change, then you can test them in a uniform way and develop "expectations" which will augment your trust in additive, pigments, and some arbitrary results.

[@RublevColours]

There are no additives in the paints tested. Only oil and pigment, so the anomalies may be due to operator errors or something else.

[@deadlyradiation7977]

What is the ASTM Standard White? Thank you.

[@Divertedflight]

A mix of blanc fixe or barite, titanium white, and zinc white. It's mentioned in this very same video at 7:48

[@deadlyradiation7977]

@@Divertedflight Thank you! I missed that.

[@phillipmurphy842]

Is there a control for heat in these experiments ?

[@RublevColours]

Test samples in both the outdoor under sunlight and indoor artificial light are exposed to heat. This is not controlled but it is consistent with both exposures. The exposures in Arizona and South Florida are done between the months of October and March.

[@MoonPlayingSaxophone]

Heroes

[@keepyourshoesathedoor]

How did that happen?🤨

[@keepyourshoesathedoor]

And QOR (allegedly) does their own tests.

[@RublevColours]

Watch the video because it explains why the ASTM test method is not accurate.

[@angelopicone2223]

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