Restoration of Ming dynasty Jin zhe si: a lost Chinese goldsmithing technique

Hubei Province was a significant center for Ming Dynasty vassal princes, whose tombs have yielded exceptional gold jewelry. A distinctive but lost technique, “Jin zhe si,” characterized by ultra-thin folded and corrugated gold sheets (foils) with a unique satin texture, remains poorly understood. This study investigates gold gourd earrings from the tomb of Prince Zhu Zairong (d. 1545) through micro-analysis and experimental archaeology. By combining historical records with reverse engineering, we analyzed the manufacturing process and the crucial role of material properties. Comparative experiments using gold, silver, and aluminum foils demonstrated that the superior ductility of high-purity gold is essential for achieving the complex hyperbolic folding without fracture. The successful replication of these artifacts bridges the gap between ancient textual descriptions and material evidence. This interdisciplinary approach provides new insights into Ming Dynasty metalwork and contributes to the preservation of traditional goldsmithing craftsmanship.