Canvas, ARTISTS'

Canvas, ARTISTS', the principal material upon which oil-paintings are made. Before it is put into the artist's hands it is usually primed, or ground of a neutral gray, or other tint, as he may direct. Certain sizes of canvas being in greater request than others, are kept ready mounted on wooden stretchers. The stretchers are provided with wedge-shaped keys at the corners, for tightening the canvas, should it become slack. Those used for portraits are known by the names of kit-cat, which measures 28 or 29 inches by 36; three- quarters, 25 by 30 inches; half-length, 40 by 50; Bishop's half-length, 44 or 45 by 56; Bishop's whole length, 58 by 94.