Gouache paint was first used in the 14th century in the illustrations of
illuminated manuscripts. It is very similar in many ways to
watercolor paint, and when
thinned down a lot, its appearance is almost indistinguishable from watercolor. The major difference between the two is the addition of
Chinese white (which is a
zinc white rather than a
lead white), mixed into
gum arabic and then added to the colored
pigment. In this way it is also similar to
tempera, and is sometimes
mislabeled as such, though true tempera actually uses
egg yolk.
In
the 20th century, Gouache has been used extensively for
posterwork, since its
matte finish
photographs well, and is easy to duplicate with a print. This flat,
velvety look is the major visual difference between watercolor and gouache. Most paintings in the medium are works on paper or board, though gouache can also be used on
canvas, and has even been used to create
cells in
animation over watercolor backgrounds.
One of the really cool things about gouache is that it is (to my knowledge) the
only opaque paint that can be
reconstituted. Paint which is allowed to dry in a plastic watercolor
palette can be reconstituted even months later and maintain its quality and
lightfastness.
Suggestions for working with gouache:
- Play around with various opacities.
- Now try thinning the tones with permanent white instead of water. See? Two palettes for one!
- Don't overbrush! Gouache tends to do really neat things if you leave it alone, even making your mistakes look super-cool.
- To create water-resistant colors, mix paint with acrylic glaze medium. This will also keep paint from bleeding up through if you decide to paint washes over background layers.
- Usually, people use watercolor brushes when painting with gouache, but there are all kinds of nifty effects you can create using different kinds of brushes, too.
RESOURCES:
http://en.wikipedia.org/wiki/Gouache
http://webexhibits.org/pigments/indiv/history/zincwhite.html
Artist's Manual. Angela Gair, ed. Chronicle. San Francisco, 1995.
Pratt Institute, freshman year Light & Color Design class with professor William Sayler