Note: The variety of terms is due to the regional differences in foundry terminology. Forma is the total of all layers of investments ready to cast. Camicia or tunica are the first fine refractory clay layer applied directly on the wax. Mantello or cappa are the second coarser layer, often made of refractory clay, thick cloths, iron belts to help containing the pressure developing during the pour. (Add link or ref to “refractory mold?)