During the Bronze Age, vessels like this jue, or tripod ritual wine vessel, were buried with members of the Shang and Zhou aristocracy as symbols of power. Made of a copper and tin alloy, they were produced using the piece-mould casting method, which first appeared in the North China Plain about 1500-1300 B.C.E. This ancient method consists of making a clay model of the vessel, shaping a clay mould around it and then, when hardened, cutting the mould in sections. Decorative patterns are then carved or impressed directly on the inner surface of the mould before firing. After firing, the mould is ready for casting. The parts are reassembled around a core so that the final vessel will be hollow. Metal spacers are applied around the core to allow the bronze to flow through. When the bronze has cooled, the mould and core are removed to reveal the finished vessel. Thanks to this method borrowed from ceramic technology, the bronze casters achieved incredible accuracy in rendering even the most complex designs.