Pigment Properties

A visual effect in watercolor painting where heavier pigment particles settle into the micro-valleys and textured indentations of watercolor paper, producing a mottled, organic texture rather than a flat, uniform wash.

A watercolor paint made from one Colour Index pigment, such as French Ultramarine labeled PB29 alone, as opposed to a convenience mix that combines two or more pigments in one tube. Manufacturers print the pigment codes on the tube label and color chart, which is how to tell the two apart.