Planishing is a skilled technique, whereby a planishing hammer is used to hammer a patterned finish into the surface of a metal (normally sheet metal).

Copper is often given a planished / hammered finish. The copper is first softened through a heat treatment process called ‘annealing’. It is then cleaned to remove any ‘dirt’, before being planished. As the copper is ‘planished’, it is rotated on the stake. This gives the copper it’s distinctive planished pattern. Planishing also hardens the metal, ensuring the final shape (such as a bowl) has the strength to resist drops and knocks.
The planishing technique is important in the shaping of sheet metal, as well as improving the surface aesthetics.