1911 Encyclopædia Britannica/Gouache
GOUACHE, a French word adapted from the Ital. guazzo (probably in origin connected with “wash ”), meaning literally a “ford,” but used also for a method of painting in opaque water-colour. The colours are mixed with or painted in a vehicle of gum or honey, and whereas in true water-colours the high lights are obtained by leaving blank the surface of the paper or other material used, or by allowing it to show through a translucent wash in “gouache,” these are obtained by white or other light colour. “Gouache” is frequently used in miniature painting.