Carving is a subtractive process. A carver removes bits and pieces of a hard material, slowly revealing the desired shape. Many different things can be carved – stone, marble, wood, plaster, plastic, bone, even soap. Some materials are much harder than others; stone is harder than wood, for example, but some stones are harder than other stones and some woods are harder than other woods! The tools carvers use vary according to the material, but the chisel – a sharp blade with a long handle – is used in almost all kinds of carving. A wooden hammer called a mallet is used to tap the chisel from the back.