slipcasting

Slipcasting is a technique for the mass-production of pottery and ceramics, especially for shapes not easily made on a wheel. A liquid clay body slip (usually mixed in a blunger) is poured into plaster moulds and allowed to form a layer, the cast, on the inside cavity of the mould. In a solid cast mould, ceramic objects such as handles and platters are surrounded by plaster on all sides with a reservoir for slip, and are removed when the solid piece is held within. For a hollow cast mould, once the plaster has absorbed most of the liquid from the outside layer of clay the remaining slip is poured off for later use. The cast piece is removed from the mould, "fettled" (trimmed neatly) and allowed to dry. This produces a greenware piece which is then dried before firing, with or without decoration and glaze. The technique is suited to the production of complex shapes, and is commonly used for sanitaryware, such as toilets and basins, and smaller pieces like figurines and teapots. The technique can also be used for small-scale production runs or to produce limited editions of objects, especially reproductions of antique dolls and modern porcelain doll-making.