Editing Gouache (section)

== Description ==
Gouache paint is similar to [[watercolor]], but it is modified to make it [[Opacity (optics)|opaque]]. Just as in watercolor, the binding agent has traditionally been [[gum arabic]] but since the late nineteenth century cheaper varieties use [[dextrin|yellow dextrin]]. When the paint is sold as a paste, e.g. in tubes, the dextrin has usually been mixed with an equal volume of water.<ref name="Doerner1977"/> To improve the adhesive and [[hygroscopic]] qualities of the paint, as well as the flexibility of the rather brittle paint layer after drying, [[propylene glycol]] is often added.<ref name="Doerner1977"/> Gouache differs from watercolor in that the particles are typically larger, the ratio of pigment to binder is much higher, and an additional white filler such as chalk—a "body"—may be part of the paint. This makes gouache heavier and more opaque than watercolor, and endows it with greater reflective qualities.<ref name="wash_gou">{{cite book|last1=Cohn|first1=Marjorie|title=Wash and Gouache|date=1977|publisher=Center for Conservation and Technical Studies, Fogg Art Museum|location=Cambridge|isbn=0916724069|url-access=registration|url=https://archive.org/details/washgouachestud00cohn}}</ref>

Gouache generally dries to a [[Lightness|value]] that differs from the one it has when wet (lighter tones generally dry darker and darker tones tend to dry lighter), which can make it difficult to match colors over multiple painting sessions. Its quick coverage and total [[hiding power]] mean that gouache lends itself to more [[direct painting]] techniques than watercolor.<ref name="imed_tech">{{cite book |first=Adolf |last=Dehn |title=Water Color, Gouache, and Casein Painting |publisher=Studio |place=New York |date=1955 |oclc=1192031}}</ref> "[[En plein air]]" paintings take advantage of this, as do the works of [[J. M. W. Turner]].

Gouache is today much used by commercial artists for works such as posters, illustrations, comics, and for other design work. Most 20th-century [[animation]]s used it to create an opaque color on a [[cel]] with watercolor paint used for the backgrounds. Using gouache as "[[poster paint]]" is desirable for its speed as the paint layer dries completely by the relatively quick evaporation of the water.

The use of gouache is not restricted to the basic opaque painting techniques using a brush and [[watercolor paper]]. It is often applied with an [[airbrush]]. As with all types of paint, gouache has been used on unusual surfaces from Braille paper<ref>Vienna Parreno has painted on Braille paper. {{cite web|title=Beyond Retinal Titillation: Seeing Red: Blog: Vienna Parreno|url=http://viennaparreno.wordpress.com/2008/07/21/beyond-retinal-titillation/|access-date=2008-07-23|archive-url=https://web.archive.org/web/20080801090654/http://viennaparreno.wordpress.com/2008/07/21/beyond-retinal-titillation/|archive-date=2008-08-01|url-status=dead}}</ref> to [[cardboard]]. A variation of traditional application is the method used in the ''gouaches [[decoupage|découpées]]'' (cut collages) created by [[Henri Matisse]]. His ''[[Blue Nude II|Blue Nudes]]'' series is a good example of the technique. A new variation in the formula of the paint is ''acrylic gouache''.