Relief is a sculptural technique where the sculpted elements remain attached to a solid background of the same material. The term relief is from the Latin verb relevo, to raise, to create a sculpture in relief is to give the impression that the sculpted material has been raised above the background plane. What is actually performed when a relief is cut in from a surface of stone or wood is a lowering of the field. The technique involves considerable chiselling away of the background, which is a time-consuming exercise. In other materials such as metal, clay, plaster stucco, ceramics or papier-mâché the form can be just added to or raised up from the background, and monumental bronze reliefs are made by casting. There are different degrees of relief depending on the degree of projection of the form from the field. There is also sunk relief, which was restricted to Ancient Egypt. However the distinction between high relief and low relief is the clearest and most important, and these two are generally the only used to discuss most work. Hyphens may or may not be used in all these terms, works in the technique are described as in relief, and, especially in monumental sculpture, the work itself is a relief. Reliefs are common throughout the world on the walls of buildings and a variety of settings. Relief is more suitable for depicting complicated subjects with figures and very active poses, such as battles. Most ancient architectural reliefs were painted, which helped to define forms in low relief. Rock reliefs are carved into solid rock in the open air. This type is found in cultures, in particular those of the Ancient Near East and Buddhist countries. A stele is a standing stone, many of these carry reliefs. The distinction between high and low relief is somewhat subjective, and the two are often combined in a single work. In particular, most later high reliefs contain sections in low relief, a low relief or bas-relief is a projecting image with a shallow overall depth, for example used on coins, on which all images are in low relief. Other versions distort depth much less and it is a technique which requires less work, and is therefore cheaper to produce, as less of the background needs to be removed in a carving, or less modelling is required
A face of the high-relief Frieze of Parnassus round the base of the Albert Memorial in London. Most of the heads and many feet are completely undercut, but the torsos are "engaged" with the surface behind.
A common mixture of high and low relief relief, in the Roman Ara Pacis, placed to be seen from below. Low relief ornament at bottom.