slipcast

Slip casting is a ceramic forming technique in which a liquid clay slip is poured into a plaster mold. The plaster’s porosity draws water from the slip, allowing a uniform hollow shell to build up on the interior. Once the desired thickness is reached, excess slip is poured back, and the shell is left to stiffen. The piece is removed from the mold while leather-hard, dries further, and is assembled from multiple parts if needed. After drying to bone-dry, it is bisque-fired to remove water and harden the body, then glazed and glaze-fired.

Molds are usually made of gypsum plaster and can be multi-part to create complex shapes. Slip must be consistent in composition and temperature; plaster molds are often pre-wedged. Clean release agents or mold seams are common, and some studios use vacuum or centrifugation to improve wall thickness uniformity.

Slip casting is well suited to mass production and the creation of precise, thin-walled forms with complex interiors, including dinnerware, figurines, and hollow ware. It enables rapid production of multiple identical pieces but requires access to plaster molds and can lead to porosity or warping if mismanaged. After firing and glazing, the results are durable ceramic wares. Originating in Europe in the 18th century for porcelain and later adapted to stoneware and earthenware, slip casting remains a central method for reproducing consistent, intricate forms.