Lost wax casting or "precision casting" is a particular technique for faithfully reproducing complicated metal parts, even very small ones, advantageously replacing long assembly operations. The original model is faithfully copied with special silicone elastomers and then reproduced in wax. In turn, the wax copies (positive reproductions of the original) will be covered with special ceramics. The forms obtained are then cooked for many hours allowing the wax to flow away, leaving the impression in its place which will then be filled by the molten metal.