When pieces are moulded or thrown, the mass to be processed is brought to a consistency different from that used for casting. The filter cake is mixed, deaerated and thickened in an aggregate. With quite a bit of skill, the proper moisture content of the mass is achieved. Parts that are to be thrown, such as plates, are not freely moulded on the wheel. Unlike for pottery, the special product's hollow mould is placed on a rotating disc into which the mass is rotated.