Once the wax model has been retouched, and the casting system and nails affixed, the model is in turn packed in the chamotte mixture. For this, forms made of sheet metal or wood are built to correspond to the size of the wax model. Smaller parts are immersed in chamotte, while larger ones are filled.

The chamotte mixture consists of plaster, recycled and new chamotte (fireclay). The chamotte molds yield a lively raw casting patina, which is valued by many clients.

The mixture is sprinkled into water in a special machine, and stirred under a vacuum in order to obtain a pore-free and exact surface. The hardened molds are placed in the kiln with the casting cup facing downwards so that the wax can flow out and the hollow cavity desired is created.