Dear MITRA people. I have a large amount of Gamblin PY3 oil-based etching ink but have been reading recently that the lightfastness of this pigment is questionable. On further reading about it in the Just Paint newsletter from Golden in an article from 2018 about changes to their yellow range in acrylics, it seems that this poor rating is based on its behaviour as a tint when mixed with titanium white and it was suggested that there might be some sort of adverse synergy going on between them in acrylics.
This article however also mentioned that it was performing well in oils (and strangely, watercolours). I do know lots of oil painters who feel it should be avoided, What is your opinion of the lightfastness of this pigment in oils (whether paint or printmaking ink) and would it be fair to imagine that if I use it in mixtures that don’t include a white, it should be reasonably reliable?
Thanks Brian but I’m a bit confused. Are you saying PY3 is not permanent even in oils?
Thanks Brian and Mirjam Very helpful. Excellent article explaining lightfastness. Just wondering though, if I glaze a more permanent colour over a less permanent one, does that help to protect the weaker under-colour at all?
I may be grasping at straws here but am trying to find a way to get some use out of my PY3 printing ink. It seems almost impossible to get a truly permanent yellow in etching or relief printing inks…
If you mix a small amount of the Gamlin Etching Ink Yellow Ochre (PY43) you might increase lightfastness (Iron oxides are used with an organic pigment in the paint industries). Of course it will effect the chroma and lightness of the Hansa Yellow Light (PY3). Whether a small amount will help much I don’t know, although PY3 is I believe quite a strong tinter so you might be able add more than with a weaker tinting pigment.
Richard Phipps
Golden is on the forefront of this discovery of the change in lightfastness rating for PY3. There is little that I could add. Maybe our representative from Golden has additional info, I will message them about your post.
Sorry that is not what I meant. I was trying to say that a pigment that is less than lightfast would survive better is untitnted but would remain less that permanent. I was not commenting specificall on PY3. I will remove that sentense so as to not confuse people in the future.
When we tested PY3 in oil paint we observed acceptable lightfastness in both masstone and tint. In oil PY3 had Delta E changes that fall in the upper half of the LF 2 range, which is Delta E 4-8. However, that is a change, which would be noticeable by eye. To get an idea ASTM lightfast ratings we have an article here: https://www.justpaint.org/delta-e/
Mirjam Hintz (Golden Artist Colors)
