Everyone’s heard of oil paints and acrylics—but what is “gouache”?

Gouache (which is pronounced /gwash/) is a paint made by dissolving ground pigments in water and then thickened with a glue-like substance (usually gum arabic or yellow dextrin).  It is applied like oils and acrylics but like watercolors it tends to be absorbed into the paper on which it is painted.  Unlike watercolors, it can also be applied to make bold, flat, and completely opaque colors.  Gouache has been used for well over 1000 years, but it became popular for commercial artists in the 20th century because it photographed well and could be used to make crisp images and lettering (particularly when mixed with an acrylic binder instead of gum arabic).  The term is French, derived from the Italian word “guazzo”.