HOLLOWWARE

hollow metal utensils and artifacts. The simplest metalwork technique for making hollowware is to join pieces of sheet metal together, using rivets, solder, or other means. A riveted bucket is a simple example. Raising, a technique dating from at least the 3rd millennium BC, is commonly used for hollowware in silver, copper, and other malleable metals: a disk of sheet metal is gradually shaped into a hollow form over a stake or anvil by a series of hammer blows spiraling from the centre of the convex side; the hammer marks are later removed with a smooth, planishing hammer. Casting in metal, sand, or other molds is used for metals unsuitable for hammer work. Bronze vessels and most pre-19th-century pewter objects have either been cast whole or made up from several separate castings. Spinning, a technique that originated in the early 19th century, can be used for most metals. A metal disk is set on a lathe behind an appropriately shaped metal or wooden chuck, and during rotation the metal is pressed onto the chuck with a tool. Britannia metal was often spun; a typical, modern spun object is the aluminum saucepan. As in most metalworking techniques, the metal is periodically softened by annealing, or heating, when it has become hardened through being worked. Combinations of techniques are often used. The term hollowware also refers to certain types of pottery and treen (wooden objects).