Classroom Buzz: Gouache- Eric Burton's Research

It is great teaching my watercolor class with so many talented and enthusiastic students who are participating. For his class presentation, Eric Burton covered some general points on materials needed for gouache which is featured on this blog. Most students have tried it and love it. I call gouache “the magic elixir.” Here are Eric’s basic materials for anyone wanting to get started:


The definition for gouache is rather ambiguous and is placed under an umbrella of specific to general terms such as casein tempera, tempera, show-card color, designer’s color, body color or any transparent watercolor that is mixed with Chinese white. When studied thoroughly, however, one finds that gouache is not casein tempera nor does it easily lend itself to the over-all term of tempera paint. Neither is it exactly designer’s color as they contain bright pigments that are not lightfast and yet may be “used as gouache colors with certain restrictions” (Mayer “Painter’s Craft” 33). So the word gouache can be applied in very general or specific instances, depending on the user’s intent.
Clearly put, gouache is simply an opaque watercolor. It differs from watercolor in that it contains a greater amount of a binder consisting of gum arabic which in turn gives the pigment more body. The gum arabic is bonded with precipitated white chalk, white paint or both, and provides the paint with a translucent quality. Due to this bond, gouache does not rely on the reflective quality of the surface of which it is placed as watercolors do. The inclusion of the white pigment allows the gouache a “brilliant light-reflecting quality” and since its brilliancy “lies in the surface itself”; it provides the paint with a whiteness or brightness not found in traditional watercolor (Mayer “Artist Handbook” 292).
Gouache dries quickly to a soft, somewhat chalky, matte surface, allowing the finished appearance a “subtle feeling” (Quiller & Whipple “Water Media Techniques” 18). Darker colors tend to dry lighter and conversely lighter colors will dry darker than they initially appear. It is highly recommended that existing colors be mixed a little at a time until the desired color and intensity is obtained. Violet cannot be obtained by mixing red and blue gouache due to their light refraction qualities but instead a brownish, muddy color will result.
With excellent flowing capability, gouache can be used for the smallest of detail or to sufficiently cover large, flat areas. When applied wet on wet the colors blend easily but the fusing becomes much more difficult when the gouache begins to dry. Once dried, the paint may be intentionally lifted with a clean, wet brush but this characteristic makes correcting a mistake difficult as under-layers can lift and may result in an unintentionally blotchy appearance. This can be avoided by combining “ten parts of water with one part acrylic matte medium” to the gouache, thus making the under-layer insoluble and secure (Quiller & Whipple “Water Media Techniques” 16). When used opaque, gouache looks thicker than it actually is and should be applied in layers to avoid too thick of an application. If applied in an impasto manner the gouache will eventually crack due to its brittle properties. Although not designed for washes, when distilled gouache provides a softer more diffused but less brilliant appearance than that of transparent watercolor.