Slumping is a technique employed to reshape existing glass into a new form. It involves heating a flat sheet of glass to a temperature that softens it without melting it completely. This temperature typically ranges between 1,200°F to 1,500°F (about 650°C to 800°C). Once the glass reaches this pliable state, it is placed over or into a mold. As it cools, the glass adopts the shape of the mold, creating a variety of forms, from simple bowls to complex sculptures.