The ancient Chinese used a technique known as “piece-mold bronze casting” to make their ritual vessels and other bronze work. The first step was to make a clay model of the entire piece, including all of the decorations. Another heavier clay was then packed around this model, which formed a mold. After the clay dried, the mold was cut into pieces which released the interior model. The mold, now reassembled, could be filled with molten bronze. Bronze, an alloy of tin and copper, plus other metals, becomes molten at 1,800 degrees and requires an enormous amount of labor to manipulate.