Coin Collecting - Coin Design

The process of minting begins with the creation of a coin design. Initially this is worked out on paper or with a computer graphics program. This allows for changes as the design is developed. Once a final design has been approved a three dimensional version is created. This original may be created in plaster, clay, or modeling wax (or some combination thereof). This initial model will be large enough for the artist to work in details easily and will be several times larger than the final coin. If the original was produced with clay or wax, a final plaster model will be produced from the original.

Sketch_Designs_for_Coin

A silicone rubber mold is then made from the plaster model. The rubber is poured over the original model and, when the rubber hardens, it will create a negative impression of that original. Silicone captures very fine details and, thus, is admirably suited for this purpose. From the silicone mold a hard plastic (epoxy resin) cast will be made. Liquid epoxy is poured into the rubber mold and, when the plastic hardens, it will be an exact duplicate of the original plaster model. Every detail of the original will be captured, but the epoxy will be much harder and more durable than the plaster. The epoxy copy of the original model is referred to as a "galvano" and it will serve as a template from which the coin dies will ultimately be prepared. A separate galvano is necessary for both the front (obverse) and back (reverse) of the coin.

Galvano_Compared_to_Coin