How did artisans transfer detailed patterns from molds onto Chinese bronze objects?

Artisans in ancient China utilized a sophisticated piece-mold casting process to transfer detailed patterns onto bronze objects. This technique involved two primary methods for applying surface decoration:

• Direct Incision on the Model: Artisans could add designs directly to the surface of the clay model before the mold was applied. This required a double transfer process, moving the design from the clay model to the clay mold and finally to the bronze surface.1
• Direct Incision on the Mold: Alternatively, patterns were incised directly into the interior surface of the mold sections after they were removed from the model. Because the design was carved in reverse into the mold, it produced a raised design on the finished bronze object.21

These methods allowed for the creation of intricate zoomorphic and geometric motifs, such as the taotie, which reached high levels of complexity and sharpness by the end of the 2nd millennium BCE. Once the molten bronze was poured into the assembled mold and cooled, the mold was broken away to reveal the decorated object.12