Embossing (Repoussé)

Unless you are a real art follower, chances are that you have never heard of metal chasing or Repoussé.  

Repoussé (rəpūsā in French) or repoussage is a metalworking technique in which a malleable metal is ornamented or shaped by hammering from the reverse side to create a design in low relief.

There are few techniques that offer such diversity of expression while still being relatively economical. Chasing is the opposite technique to repoussé, and the two are used in conjunction to create a finished piece. 

This process of stretching, raising and sinking of the metal is also known as Embossing.