A veneer is very much like a contact lens. It is an extremely thin sheet of porcelain that bonds to the front of your tooth. They are used to change the shape, color, size, and symmetry of the teeth and smile. The porcelain is thin, on the order of 0.3 to 1 mm, about the thickness of one to two business cards. Porcelain is the material of choice because it most naturally replicates human enamel.