Water Colors are pigments prepared for the use of artists and others by mixing coloring substances in the state of fine powder with a soluble gum such as gum arabic. These are made up in the form of small cakes, which are rubbed down with water and applied with a brush to paper, ivory, and some other materials. Moist water colors are made up with honey or glycerin as well as gum, and are prepared so as to be kept in small earthenware pans or metal lie tubes. Dry cakes require to be rubbed down with water on a glazed earthenware palette or slab, but moist colors can be mixed with water for use by the friction of a brush, so that the japanned lid of the box which contains them serves for a palette. The latter are accordingly very convenient for sketching from nature.
In water-color painting two methods are employed; by one the artist works in transparent colors, by the other in opaque or body colors. In working by the latter method, which somewhat resembles on painting in its nature, Chinese white is mixed with light colors to give them body. Not only is there much artistic work done solely in transparent colors, but it is almost always these that are used for tinting mechanical drawings, maps, and the like. Some artists freely combine transparent, semi-transparent, and opaque colors. The quick drying of the water-color pigments is favorable to rapid execution; and greater clearness is attained than is practicable in oils. In water-color painting the texture of the paper employed is often of importance. Water-color drawings are of course more easily injured by damp than oil painting.