Prized for the luminosity of its transparent colors, watercolor is a water-based medium that is applied by brush, typically to white paper. Packaged in cakes of color known as "pans," or in tubes of thickened paint, it is composed of finely-ground pigment combined with water and gum arabic, a binder that disperses the pigment particles to create a uniform solution and adheres it to the support. Modern watercolors form washes with only a touch of water, allowing greater ease of use. More Information