Repoussage

Repousse, meaning "to push back", is an ancient technique used by artists to give form to metal. The technique involves applying pressure to the front and back of a piece of metal ultimately creating a raised design or pattern on the surface and depending on the plasticity of the metal a range of detail and depth can be achieved.

Contemporary artists begin by drawing the outline of a design onto a piece of annealed metal, preferably twenty to twenty-two-gauge. Pitch, typically held in a pitch pot, is warmed with a low torch and the metal piece is placed on a smooth area of the pitch surface. A small amount of pitch is pinched up around the metal firmly mounting the piece to the pitch bowl. A tracer punch is then used to re-trace the design onto the exposed surface of the metal. Next, the pitch bowl is re-heated, the metal piece is removed, and the pitch residue is either burned off or dissolved with baby oil or turpentine. Finally, the metal piece is turned facedown and reinserted into a warmed pitch bowl so that the artist can begin to raise the design. In order to create a well-defined form the metal must be worked from both the front and back. As it is being formed, the metal will become work-hardened and must be removed from the pitch, annealed, and re-inserted or the artist risks damaging the integrity of the piece.

Repousse tools are typically made by hand from either steel rod or wood and can provide a range of effects. Round tipped modeling tools are used to raise the general body of the form, tracing tools are used to make lines, and curved punches are used to spread the metal surface into rounded forms. Matting tools are used to create surface texture while planishing tools are used to give the metal a smooth surface.

Reference The Complete Metalsmith written by Tim McCreight