Riveting hinge were a traditional practice on acetate frames in order to fasten hinges to the frame and temples. This is a handcraft and required experienced worker. This practice usually requires a Rivet Punch to rivet hinges and excess pieces to frames. When riveting a acetate frame, a hinge usually with 2 holes and metal pins pieces are used. The pins pierce the set holes on the acetate frame and continue through the set holes on the metal hinge. The pins are then punched on the other side of the metal hinge creating a mushroom effect on the end, preventing the pins from backing out.