MITRA Forum Question Details

Hello there,

It doesn't yellow much, however it contains zinc white (to yellow less) and safflower oil which is particularly slow drying (but yellows less).

Meaning you're very likely to see cracks appear on the subsequent layers, if you didn't thin it down much with solvent and/or apply it thickly and don't leave it plenty enough of time to dry. And if You painted a very smooth layer with it, you might have issues of adherence with the next layers over time.

So it's surely doable with experience but that's a risky colour for grounds. I'd keep the W&N white heavily diluted, thinned and mixed with ochres as much as possible for lower layers, and put forward its quality for the top layers.

Safer (and non yellowing) white ground would be acrylic gessos. 

Good luck and cheers,

Lussh​

i have looked at various yellowing tests and the only oil-based white that I saw that didn't yellow (when compared with acrylic-vehicle whites) was an alkyd by CASS​

My post was cut off for some reason, so here it is again:

i have looked at various yellowing tests and the only oil-based white that I saw that didn't yellow (when compared with acrylic-vehicle whites) was an alkyd by Cass Art. However, the drawbacks of alkyds are an issue in that case (rapid drying, odor, possibly brittle paint film in the long term — although current alkyd formulations may not have that issue as older ones certainly did). 

Alternatives to alkyds that show little yellowing were ground in oils that shrink when cured (which causes brittleness) but, with one amateur's test, two of them didn't crack. (The presumably alkyd-based "Archival Oils" white didn't crack either but it was yellowish.) One was Lukas' "Opaque white" (lithopone, PW 5, ground in what I think is a mixture of safflower oil and wax). That one, though, dries rapidly due to siccative and the wax might have a solubility issue, if Lukas indeed uses wax in its formulation. The rapid drying makes it less of an alternative to that Cass alkyd. One person wrote that their Opaque White yellowed a lot so formulations can also potentially change or that person dried their paint in the dark, which causes drying oils to yellow. Lithopone has a slight green cast and that white was not as pure as the Cass alkyd.

Golden's testing showed low (but definitely not none) yellowing for even pure titanium white bound in linseed, as long as some kind of suitable additive was used to prevent the oil from rising to the surface during the drying period. The key appears to be to avoid allowing the painting to dry in the dark and to avoid, as much as possible, storing the painting in the dark.

As mentioned by the other commenter, zinc white PW 4 causes brittleness and the use of an "alternative" oil (to linseed) can cause paint film brittleness as well. That is because linseed shrinks less when cured than the alternative oils.

If you don't hang oil paintings by extremely white things, like acrylic titanium white surfaces, the white will appear less yellow, too. Hanging an oil painting done completely with linseed oil and no zinc white next to an acrylic painting that is mostly titanium white on a hospital-white wall, with bright white frames... would be the worst-case scenario. How one uses color in the painting can also make the white look whiter, such as by having areas that are very pale yellow and putting the "white" by some blue-violet. The yellowness of the pale yellow will make the pure white area seem less yellow. Another trick is to use the tiniest touch of ultramarine in one's white. That's what Permalba does.

Yellowing in oils can be reduced by using well-formulated paint and not drying the paintings in darkness. However, I think people worry too much about it, overall. I am more concerned about the cracking in zinc white formulations, which strongly harmed one of my mother's best paintings.

— SRS