Donna O'Bryan, age 16, of Davenport, Iowa, for her question:

IN ART, WHAT IS GOUACHE?

Gouche, in art, is a form of watercolor that uses opaque pigments rather than the usual transparent watercolor pigments. Gouache colors are produced by adding white pigment to regular water color paint.

Although gouache lacks the delicate luminosity of regular watercolor, it possesses a compensating substance and body approaching that of oil paint. In addition, the tendency of gouache colors to lighten on drying makes possible a wide range of pearly or paste like effects.

Gouache was first used by the ancient Egyptians who used honey to bind their pigments. Gouache was widely used in the Middle Ages for illuminating manuscripts and it became particularly popular in the 18th century with painters.

Gouache has been used extensively by artists in the 20th century who find its thick impasto (heavy paint layer) ideal for modern expressionist effects.