Gouache, a French term meaning “opaque,” is simply opaque watercolor paint. Its brightness comes from the color itself—unlike transparent watercolor, which gets its brilliance from the reflective qualities of the paper. Gouache can be used thinly, like transparent watercolors, but it is generally used as a matte, opaque paint. Gouache provides an actual paint layer, while transparent watercolor is a stain. Often referred to as “body color,” the film of gouache appears thicker than it really is.
WHAT IT IS
Gouache is made from pigment, binder (usually gum arabic), wetting agents, other minor additives, and a preservative. More pigment is used in making gouache than in transparent water-colors, which makes them opaque. An opaque extender ...