Q. Ive noticed that many artists say their palettes include Vandyke brown and alizarin crimson. But according to the Wilcox guide, these pigments are fugitive and usage is not recommended. How much of a concern should this be? And why do so many artists still use these colors?
A. Vandyke brown is a natural earth pigment that contains clay, iron oxide, decomposed vegetable materials (in the form of soil) and bitumen. Its got a pretty bad reputation: It fades and/or darkens, wrinkles and cracks in oil. I know of no manufacturer that uses this pigment in its traditional form—though its quite likely that some use a different, more stable pigment or mixture of pigments and call the resulting color Vandyke brown.
Alizarin crimson has the distinction of being the first synthetic organic pigment, introduced around 1868. Its a nearly perfect duplicate of its natural counterpart, rose madder, which was known to fade, especially in mixtures with white. While alizarin crimson is much better in that regard—it holds up fine when used full strength—it still fades unacceptably in mixtures with white. In fact, it doesnt meet ASTMs lightfastness requirements. However, its still offered on the market because its such a unique hue (a rosy dark red with a bluish undertone). Simply put, artists want to buy and use it, and thats why its still around. There are better, more permanent synthetic organic pigments that come close to duplicating the hue of alizarin. Most of these colors are based on some variation of the quinacridone group of pigments, so look for color names like quinacridone crimson.