(Photo: Leo Reynolds used under CC BY-NC-SA 2.0 license)
Metal embossing, which is sometimes called tooling or repoussee, is the craft of selectively raising sections of sheet metal in order to create relief sculpture. Copper bends easily and is thus a frequently selected metal for this craft. Once shaped, embossed copper is often patinated, which means that it is stained with reactive chemicals.
The Makerspace has supplies for copper embossing, including:
Here is a video that introduces copper embossing.