Lost-wax casting

Lost-wax casting, sometimes called by the French name of cire perdue, is the process by which a bronze is cast from an artist's sculpture. An ancient practice, the process today varies from foundry to foundry, but the steps which are usually used in casting small bronze sculptures in a modern bronze foundry are generally quite standardized.
Sand casting is mainly used for casting flat, relief-like sculptures. Aluminium is one material which is commonly used in sand-casting. The process starts with a tub filled with sand. The sand is wetted, and an object is pressed into the wet sand, or the sculptor uses his hands or tools to make the desired design in the sand, which is then dried. Molten aluminium is carefully poured into the depression and left to cool. Then the artist may choose to continue refining the object by "chasing" it or leave it with the roughened surface that is characteristic of sand-cast objects.

Bonded sand molds are used for creating more complex sculptural works. A fine grit sand is mixed with a chemical binder in a mixing machine. The resulting mixture is packable, and is carefully pressed into the detail of the pattern, or original sculpture which is to be duplicated by casting. A mold consisting of two or more pieces is created around the pattern in stages; usually each mold piece is allowed to solidify before the next piece is begun. When all the pieces of the mold are completed, they are carefully removed from the pattern, which is set aside. The hardened sand pieces of the mold may then be reassembled, leaving empty space where the pattern originally was. Metal such as aluminum, bronze, iron, or another metal may be poured into this mold cavity. The metal cools and hardens, resulting in the casting which may then be removed from the mold, chased, and finished.

The Navajo use a natural form of the bonded sand method for silversmithing, by carving molds from Tufa Rock, a fossilized volcanic ash.

Cuttlebone casting using cuttlebone as a mold is a traditional casting method used by jewellers and silversmiths for small objects, especially in taking a copy from a metal original. The fine grain of the calcium carbonate cuttlebone offers good definition, although it imparts a characteristic surface texture to the cast.