Working with clay and clay-like materials

Slip casting
Slip casting is the technique used to produce tableware in Industry. For example, virtually any mug you buy in a general china shop will have been made using this technique. First, clay is made into a casting slip. A deflocculant is added – a chemical which means the clay needs less water to become runny. This helps the casting process. The slip is then poured into a plaster of paris mould and left to stand for a period of time. The plaster absorbs the water, and the slip starts to form a “skin” or “layer” where it touches the plaster. The slip in the middle stays runny. Once this “skin” is thick enough to form the pot, the runny slip inside is poured out and the mould left to drain. The pot will then shrink away from the mould and can be carefully removed. Because the clay is used in a liquid state, very complicated shapes can be made using this technique. The mould can be used many times so multiple copies of the same object can be produced.