Artists have used watercolor paint—powdered pigment suspended in water—since antiquity. Before the late eighteenth century, artists ground their own pigments from organic and inorganic materials like minerals, dry earth, iron oxides, and crushed insects. In 1780, a major breakthrough arrived in the form of hard cakes of pigment bound together with gum, usually gum arabic. To use these, the artist would mix the paint with water using a brush or by dipping the cake in water. By the mid-nineteenth century, artists could purchase watercolors manufactured by Winsor and Newton in tubes. The saturation level of the paint depends on the amount of water added to the concentrated emulsion; artists can exercise a degree of control by adding more or less water. Both historically and now, watercolor is typically painted on special watercolor paper. Watercolor paper has a sizing applied to control the amount of absorption, and is thick enough that it will not buckle under large amounts of moisture. Watercolor may also be applied to vellum, linen, wood, and other surfaces.

Watercolor is notoriously difficult to control, and some degree of a watercolor painting must be left to chance. Artists may work in a variety of techniques: often they mix colors as they pool, still wet, on the surface of the paper. Paul Cezanne, considered an innovator in the field, waited for each color to dry before applying the next; a time consuming process that led to a rich tapestry of overlapping colors in his finished works. Many important twentieth century artists made strides in watercolor media, such as Egon Schiele, Paul Klee, and Georgia O’Keefe. Contemporary artists working in watercolor include Till Freiwald, Jennifer Levonian, Carl Palazzolo, and Melissa Meyer.