Part 2. How paints and surfaces create color
A paint is a layer of pigment particles in a mostly clear binder, sitting on a ground. The binder is the glue that holds the particles and dries to a film, acrylic in every paint measured here, and the ground, or substrate, is whatever the paint is on, such as primed canvas, board or paper. Part 1 treated a surface as a reflectance curve and asked what the eye does with it. This part asks where the curve comes from, starting with what happens to light inside the layer and ending with the pigments themselves. Its last lesson sets out the model used for every mixture in the rest of the paper and how far it can be trusted.