Gouache

Gouache(from the Italian guazzo, "water paint, splash") is a type of paint consisting of pigment suspended in water. Gouache differs from watercolour in that the particles are larger, the ratio of pigment to water is much higher, and the presence of an inert white pigment such as chalk. This makes gouache heavier and more opaque, with greater reflective qualities.

History

Guazzo was originally a term applied to the early sixteenth century practice of applying oil paint over a tempera base. The term was applied to the watermedia in the eighteenth century in France, although the technique is considerably older. It was used as early as the 12th century in Islamic art and as early as the 14th century in Europe.

Application

Gouache dries slightly lighter than it appears when wet, which can make it difficult to match colors over multiple painting sessions. This, combined with its quick coverage and total hiding power, mean that gouache lends itself to more immediate techniques than watercolour. En plein air paintings take advantage of this, as do works by J.M.W. Turner.

Modern applications of gouache depend upon these qualities for pragmatic, rather than aesthetic reasons. Most 20th Century animations used it create an opaque color on a cell with watercolor paint used for backgrounds, and gouache as "poster paint" is desirable for its speed and durability.