Patina Process Set. Sample specimens selected from the stages of applying a patina; the steps indicative of the finishing process of a medallic item. A patina process set of a bronze medal is most spectacular because of the dramatic changes in color from one step to the next, from the shinny-penny red of a fresh struck specimen, to the dull gray of a sandblasted one, to a black-brown of the oxidizing agent, to the two-toned relief of the finished medal. See process set, finish and finishing.