If the altar stood free in the choir, and the altar-piece was to be seen from behind as well as from before, both sides were covered with painting (Norton, Church Building in the Middle Ages). The decorative screen, retable, or reredos is also called an altarpiece. (See ALTAR-SCREEN.)
Altar-Protector.—A cover made of cloth, baize, or velvet which is placed on the table of the altar during the time in which the sacred functions do not take place. Its purpose is to prevent the altar-cloth from being stained or soiled. It should be a little wider than the table and somewhat longer than the latter, so that it may hang down several inches on each side and in front. It may be of any colour (green or red would seem to be the preferred colours), and its front and side edges are usually scalloped, embroidered, or ornamented with fringes. During the divine services it is removed (Cong. Sac. Rit., 2 June, 1883), except at Vespers, when, during the incensing of the altar at the “ Magnificat”, only the front part of the table need be uncovered, and it is then simply turned back on the table of the altar. It is called the vesperale, the stragulum or altar-cover. It need not be blessed.