MITRA Forum Question Details

​Brian and Matthew, just a quick addition on using RSG. I like the strong adhesion of the linen to the maple board. The one time I tried acrylic dispersion size, it may not have been the correct material, but there were air bubbles. I didn't get the strong, even, adhesion I was looking for.

​Thank you for the link Brian. I just read it. Very informative! My apologies, I responded to your storage and medium question on the main page of the forum. Sorry about that. I am still trying to figure out the yellowing issue. 

I doubt it's the varnish.

The Neo Meglip will be an alkyd which might cause a little yellowing, but not I imagine to the degree of "disaster." 

Do you know if the titanium white is solely titianum oxide without any zinc white?  Many years past I tested a series of whites and was surprised how much a titianum white bound in poppy or safflower had yellowed in a room not exposed to much sunlight.  It was a single pigment artists range proporting to be of highest quality.  Although the painted sample was lean I believed there might have been an very slight and even surface float of poppy oil in drying. This was not present in the titanium/zinc mixes, the lead/zinc safflower mixes, or the lead in safflower.  The only sample that yellowed more was a lead/zinc primer in linseed. 

Zinc oxide seems to reduce yellowing.  Unfortunately it also increases embrittlement.  Damned if you do, damned if you don't.

Marc.​

​Thank you Marc! The fancy Italian oil paint says purely Titanium Dioxide as the pigment. Interesting about the varnish not being the culprit and the Galkyd medium possibly responsible. I completely agree with you about "Damned if you do, damned if you don't". That is right on!

Maryam

Was it Maimeri Puro Titanium white?  Because that's the colour with which I had the unexpected degree of yellowing. (Abet in a slightly gloomly studio.)  I didn't mention it by name previously because it was so many years ago and I didn't want to presume it still had that same trait.​

​YES!!! Yikes! That is exactly the paint I used! Thank you for sharing your experience. I am thinking of using Gamblin's Radiant White for the background of the next series. Do you think all Galkyd mediums will yellow? Thanks, Maryam

Gamblin products haven't been available until recently in my country.  Import of oil painting mediums by air is judged problematic. So to get to the point, I havent tried them. However I have heard their Galkyds are low yellowing.  They're almost all certainly lower yellowing than linseed oil.  

Jonathan Linton did a 5 year whites yellowing test which can be found online. Each white was only one sample however so it's possible that one sweeze from the tube could have variations in results due to oil separation.  Also those paints might now have different formulations.  The Radiant white yellowed considerably in the thick , but not much in the thin.  It looks a lot like loose oil from the top of the tube, so I don't completely trust the sample.  Can't help much beyond that I'm afraid.

Marc​

​Marc, thank you so much for pointing out the Jonathan Linton White Test. As my husband Nick, a fellow painter, says "worth many prostrations."  You have been super helpful! As I try to figure things out, I am heartened by Claude Monet's "Color is my daylong obsession, joy, and torment."