When I want a bright white highlight on a sketch, I often count on white gouache to do the job. All whites are created equal, right? Wrong. In fact, even all Titanium Whites are not created equal. On my sketches, I've noticed if a brand of white gouache isn't a brilliant white, or isn't opaque enough, or has an annoying sheen to it. Whether this is due to different brands of the pigment itself, or differences in the color of the binders, the whites are not the same. Consistency, texture…