Gouache is a water-based media that consists of pigment mixed with water and a binding agent, typically gum arabic. Gouache differs from watercolor, a very similar medium, because it dries opaque. Watercolor, rather, appears somewhat transparent when dry, allowing the tone of the paper support to remain somewhat visible. One reason this quality appeals to artists is gouache completely covers any underdrawing, which would remain visible in a watercolor painting. Gouache is typically sold in tubes, not unlike oil or acrylic paint. It can be diluted to the desired consistency by mixing with water. Gouache has some disadvantages compared to other paint media. For one, it can crack if applied too thickly, so the artist must carefully monitor the layers of paint as they dry. Additionally, while gouache lasts longer than watercolor, the colors can fade with exposure to light.

Invented centuries ago, gouache has a rich history. Ancient Egyptians used honey as a binder to create an opaque paint that was a precursor to today’s gouache. Gouache’s fast drying time and matte finish made it an ideal medium for the illumination of manuscripts in the Middle Ages. More recently, Henri Matisse used gouache to paint the papers he used for his famous cut outs, made primarily in the 1940s. Many contemporary artists use gouache by itself or in combination with other media, including Anna Boghiguian, Jonas Wood, Laylah Ali, Kerry James Marshall, and Hernan Bas.