in painting, is when a design, drawn with a pencil or crayon, has some one colour laid over it with a pencil, as Indian ink, bistre, or the like, to make it appear the more natural, by adding the shadow of prominences, aperture, &c., and by imitating the particular matters whereof the thing is supposed to consist.

Thus they wash with a pale red, to imitate brick and tile; with a pale Indian-blue, to imitate water and slate; with green, for trees and meadows; with saffron or French berries, for gold or brass; and with several colours, for marbles.