WATER-COLOR PAINTING, in some of its forms, was employed from the most ancient times until the middle ages, when oil was sometimes added to the gum, with which the colors were prepared. About 1410 the brothers Van Eyck, at Ghent, made improvements in the use of oil-colors, which entitle them to be called the initiators of the modern.school of oil-painters. In the method known as distemper, the pigments are ground up with size and water, or with gum-water. In ancient Egyptian paintings the colors, mixed with gum and water, were sometimes laid immediately on stone walls, sometimes on a coating of plaster, on wood, and baked or wet clay. The Greeks mixed their colors with gum, the yoke and white of eggs, and water. Sometimes, it is said, milk also was added. The gum was used to make the paint adhere after the water had evaporated. Until 1410 the Italian artists employed the distemper of the ancients; and afterward they still used it in fresco-painting. Michael Angelo employed it in his
greatest works, and thought oil-painting unworthy of a true artist. Most artists of that flay painted their easel pictures in oil, and their frescos in distemper. In the true fresco the colors, mixed with water, are applied directly to the smooth wet surface of good lime mortar, when a crystalline surface is formed, which almost excludes water. In dry fresco, the plaster, having first dried thoroughly, the artist moistens again as large a part of it as he can cover with color at a single sitting. Societies of artists in water color pictures on paper now hold a distinguished place among the various schools of painting. In New York the annual exhibitions show a great advance in excellence and variety of work.