Sometimes it is necessary to adapt the proportions of sculpture to suit its position in relation to a viewer. A figure sited high on a building, for example, is usually made larger in its upper parts in order to counteract the effects of foreshortening. This should be allowed for when a sculpture intended for such a position is exhibited on eye level in a museum.
The scale of sculpture must sometimes be considered in relation to the scale of its surroundings. When it is one element in a larger complex, such as the facade of a building, it must be in scale with the rest. Another important consideration that sculptors must take into account when designing outdoor sculpture is the tendency of sculpture in the open air—particularly when viewed against the sky—to appear less massive than it does in a studio. Because one tends to relate the scale of sculpture to one’s own human physical dimensions, the emotional impact of a colossal figure and a small figurine are quite different.
In ancient and medieval sculpture the relative scale of the figures in a composition is often determined by their importance; e.g., slaves are much smaller than kings or nobles. This is sometimes known as hierarchic scale.
Rodin, Auguste: The KissFront view of The Kiss, marble sculpture by Auguste Rodin, carved 1888–98; in the Rodin Museum, Paris.SuperStock
Rodin, Auguste: The KissSide view detail of The Kiss, marble sculpture by Auguste Rodin, carved 1888–98; in the Rodin Museum, Paris.Erich Lessing/Art Resource, New YorkThe joining of one form to another may be accomplished in a variety of ways. In much of the work of the 19th-century French sculptor Auguste Rodin, there are no clear boundaries, and one form is merged with another in an impressionistic manner to create a continuously flowing surface. In works by the Greek sculptor Praxiteles, the forms are softly and subtly blended by means of smooth, blurred transitions. The volumes of Indian sculpture and the surface anatomy of male figures in the style of the Greek sculptor Polyclitus are sharply defined and clearly articulated. One of the main distinctions between the work of Italian and northern Renaissance sculptors lies in the Italians’ preference for compositions made up of clearly articulated, distinct units of form and the tendency of the northern Europeans to subordinate the individual parts to the allover flow of the composition.
The balance, or equilibrium, of freestanding sculpture has three aspects. First, the sculpture must have actual physical stability. This can be achieved by natural balance—that is, by making the sculpture stable enough in itself to stand firmly—which is easy enough to do with a four-legged animal or a reclining figure but not with a standing figure or a tall, thin sculpture, which must be secured to a base. The second aspect of balance is compositional. The interaction of forces and the distribution of weight within a composition may produce a state of either dynamic or static equilibrium. The third aspect of balance applies only to sculpture that represents a living figure. A live human figure balances on two feet by making constant movements and muscular adjustments. Such an effect can be conveyed in sculpture by subtle displacements of form and suggestions of tension and relaxation. Relationships to other arts
Sculpture has long been closely related to architecture through its role as architectural decoration and also at the level of design. Architecture, like sculpture, is concerned with three-dimensional form; and, although the central problem in the design of buildings is the organization of space rather than mass, there are styles of architecture that are effective largely through the quality and organization of their solid forms. Ancient styles of stone architecture, particularly Egyptian, Greek, and Mexican, tend to treat their components in a sculptural manner. Moreover, most buildings viewed from the outside are compositions of masses. The growth of spatial sculpture is so intimately related to the opening up and lightening of architecture, which the development of modern building technology has made possible, that many 20th-century sculptors can be said to have treated their work in an architectural manner.
Some forms of relief sculpture approach very closely the pictorial arts of painting, drawing, engraving, and so on. And sculptures in the round that make use of chiaroscuro and that are conceived primarily as pictorial views rather than as compositions in the round are said to be “painterly”; for example, Bernini’s Ecstasy of St. Teresa (Santa Maria della Vittoria, Rome).
The Ecstasy of St. Teresa, marble and gilded bronze niche sculpture by Gian Lorenzo Bernini, 1645–52; in the Cornaro Chapel, Santa Maria della Vittoria, Rome. Scala/Art Resource, New York
The borderlines between sculpture and pottery and the metalworking arts are not clear-cut, and many pottery and metal artifacts have every claim to be considered as sculpture. Today there is a growing affinity between the work of industrial designers and sculptors. Sculptural modeling techniques, and sometimes sculptors themselves, are often involved, for example, in the initial stages of the design of new automobile bodies.
The close relationships that exist between sculpture and the other visual arts are attested by the number of artists who have readily turned from one art to another; for example, Michelangelo, Bernini, Pisanello, Degas, and Picasso. Materials
Any material that can be shaped in three dimensions can be used sculpturally. Certain materials, by virtue of their structural and aesthetic properties and their availability, have proved especially suitable. The most important of these are stone, wood, metal, clay, ivory, and plaster. There are also a number of materials of secondary importance and many that have only recently come into use. Primary
Throughout history, stone has been the principal material of monumental sculpture. There are practical reasons for this: many types of stone are highly resistant to the weather and therefore suitable for external use; stone is available in all parts of the world and can be obtained in large blocks; many stones have a fairly homogeneous texture and a uniform hardness that make them suitable for carving; stone has been the chief material used for the monumental architecture with which so much sculpture has been associated.
Stones belonging to all three main categories of rock formation have been used in sculpture. Igneous rocks, which are formed by the cooling of molten masses of mineral as they approach the Earth’s surface, include granite, diorite, basalt, and obsidian. These are some of the hardest stones used for sculpture. Sedimentary rocks, which include sandstones and limestones, are formed from accumulated deposits of mineral and organic substances. Sandstones are agglomerations of particles of eroded stone held together by a cementing substance. Limestones are formed chiefly from the calcareous remains of organisms. Alabaster (gypsum), also a sedimentary rock, is a chemical deposit. Many varieties of sandstone and limestone, which vary greatly in quality and suitability for carving, are used for sculpture. Because of their method of formation, many sedimentary rocks have pronounced strata and are rich in fossils.