How Were Ancient Chinese Bronzes Made?

Ancient Chinese bronzes consist of vessels, tools, weapons, and ceremonial objects cast in bronze, particularly during the Shang (c. 1600–1046 bce) and Zhou (1046–256 bce) dynasties. The bronze was made by melting copper with tin and, occasionally, lead, creating an alloy. The molten bronze was then used to create objects through a process called piece-mold, or sectional-mold, casting. This complex process can be broken down in the following series of steps:

1. Artisans build a clay model of the object they want to create.
2. The model is encased in clay molding.
3. The molding is cut into three or four sections (usually) and removed, becoming a mold for later steps.
4. If the object being made is a vessel, the initial model is trimmed into a core, which will become the cavity of the vessel.
5. The pieces of the mold are reassembled. For vessels the mold is assembled around the core, with metal spacers separating the mold and core.
6. Molten bronze is poured into the mold.
7. The mold is broken and taken off the object once the bronze cools.
8. Flaws and excess bronze are polished away.

Patterns on vessels were often incised into the mold itself, as this technique allowed for fine details to be transferred from mold to object. Things such as legs and handles were often cast separately and attached to the object with a lock-on pour.