Bronze, a combination of copper, tin, and small amounts of other metals, has long been prized for its preciousness, endurance, and its ability to register fine details and reflect light. Beginning about 1500, patrons became intrigued by the famed bronze collections of antiquity and began their own collections of ancient and contemporary bronzes. After much experimentation, artists in the 1500s refined a technique of making bronzes called indirect lost-wax casting. This technique made possible the production of multiple versions of the same piece.