White pigments added to colours 2008


Well-known member
From 2008 study released by Klaas Jan de Berg. White pigment additions highlighted in lime green. Probably added as colour brightener. The Titanium dioxide added to Old Holland's zinc white has apparently caught out at least one forger creating works intended to be from before the invention of titanium white as a oil pigment.

Just looking again at this list. I think they made a mistake with the Winsor & Newton cobalt blue deep. "Zn in addition to Co, Al of pigment" The positive zinc result will likely not be an addition, but a part of cobalt blue deep itself as unlike standard cobalt blue, Zn is actually part of its make up. ( On top of that, adding a white to a 'deep' colour would strike me as an odd thing to do.) The other two cobalt blues (Rembrandt and Old Holland) in the test are the usual PB28. They should have tested like with like.
BTW, I'm not in favour of anyone adding white to a colour to brighten it up. We can do that ourselves thank you very much.

The addition of titanium dioxide to Old Hollands zinc white is an oddity to me. It won't make it any whiter. Unless they add it in an attempt to make their zinc white a fraction less brittle?
Water sensitivity tests on the same oil colours. Winsor & Newton's Cobalt blue deep didn't have good resistance, but again its not the same pigment as the other two cobalt blues. The standard W&N cobalt blue probably performs like the others.