After casting, the mother mold is cut away to reveal a plaster likeness of the subject, the positive mold for the casting of the prosthesis. In the next step (not shown), the positive mold is built up with clay to the contours of the desired creation. The "dressed up" mold is then used to make a negative mold for the actual appliance. The clay is then removed from the positive mold. The negative mold is placed over the positive mold, and the gaps between the two are filled with foam latex-matching exactly the contours of the clay that was removed.