A systematic craft: reconstructing the engraving sequence on a Chinese Warring States bronze yi vessel

The craft of bronze vessels from China’s Eastern Zhou period remains insufficiently understood, with prevailing assumptions that decorations were created with iron tools. This study re-examines these assumptions by applying a multi-analytical methodology, including three-dimensional digital microscopy, optical microscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy, to analyze a rare engraved bronze yi vessel from the Fenshuiling cemetery, dated to the mid-Warring States period (c. 4th century BCE). The investigation identifies the vessel’s engraving tools, techniques, and sequence. Findings demonstrate the vessel consists of hot-forged, leaded tin bronze. Chasing is identified as the principal engraving technique, rather than scribing. The material’s estimated hardness supports the hypothesis that high-tin bronze tools were employed. Toolmark superposition analysis reveals a complex, multi-stage engraving process. This study provides the first science-based characterization of the engraving craft, demonstrating a systematic and scheduled approach to metal decoration that challenges previous technological interpretations.