Between piece molds and lost wax: the casting of a diatrete ornamentation in early China rethought

The creation of intricate three-dimensional openwork in Eastern Zhou bronze ornamentation has long puzzled scholars. The debate centers on whether piece-mold or lost-wax casting techniques were employed. Helen Loveday identified some diatrete vessels (with external openwork shells over internal containers) as potentially lost-wax cast. This article focuses on a spherical tripod in the Metropolitan Museum of Art (the Met), a key piece in the ongoing debate. Donna Strahan, while less definitive in her skepticism than some scholars, leans against the pre-Han use of lost wax. This article uses Strahan’s work as a springboard to re-examine the evidence, arguing that the Met tripod's ornamentation strongly suggests lost-wax casting.

The author reviews existing literature, highlighting the historical shift in scholarly opinion regarding lost-wax casting in early China. Initially, the prevalent view dismissed the technique's use. The discovery of the *zun-pan* set of Zeng Hou Yi in 1978 challenged this perspective, but more recently, skepticism has resurfaced, particularly in Chinese academia. The author examines Robert Bagley's work on early Chinese bronze ornamentation, noting its misapplication by Strahan in her arguments against lost wax. The author also discusses the work of J. Leroy Davidson, Max Loehr, and Lukas Nickel, emphasizing the differing interpretations of decorative patterns and their implications for casting methods.

The author's methodology is primarily based on a close examination of the Met tripod's ornamentation, both externally and internally. This includes visual inspection aided by digital overlays and analysis of the three-dimensional structure, particularly features like “absolute undercuts” and “stepped C-shaped” forms. The author directly challenges Strahan's interpretation of these features, arguing that her piece-mold explanation is overly complex and technically implausible. The author also draws on ethnographic evidence of wax casting techniques and experimental replication studies to support the lost-wax hypothesis. The author criticizes Strahan's reliance on the presence of “mold seams” as definitive proof of piece-mold casting, arguing that such seams can also appear in indirect lost-wax processes. The author further analyzes Strahan's proposed multi-stage piece-mold process, identifying technical inconsistencies and questioning its practical feasibility. The author contrasts the Met tripod's three-dimensional interior with the two-dimensional interior of a similar piece from Shaanxi Fengxiang to further illustrate the differences between piece-mold and lost-wax techniques.

The author's key finding is that the Met tripod's diatrete ornamentation strongly suggests lost-wax casting, contrary to Strahan's interpretation. The author highlights several features supporting this claim: the presence of absolute undercuts, indicating the impossibility of extracting a piece mold without damage; the presence of stacked C-shaped forms, more easily explained by the layering of wax; and the unnecessary complexity of Strahan's proposed piece-mold construction. The author points out that Strahan's reliance on digitally overlaid images from only one side of the openwork neglects crucial information present on the interior surfaces. The author refutes Strahan's interpretation of “mold seams,” emphasizing that these markings are not conclusive evidence against lost-wax casting, particularly in indirect processes. The author provides detailed arguments against the technical feasibility and practical plausibility of Strahan's proposed piece-mold creation process, noting the lack of a clear motive for such an elaborate method. The author contrasts the Met tripod's three-dimensional interior with a similar vessel from Shaanxi Fengxiang, further supporting the lost-wax hypothesis.

The author's findings directly address the research question of whether lost-wax casting was used in pre-Han China. The evidence presented challenges the prevailing skepticism and suggests that lost-wax casting was likely employed in the creation of the Met tripod, a significant piece of early Chinese bronze artistry. The findings contribute to a broader understanding of early Chinese metalworking technology and art. The author suggests that previous debates have been hampered by overly simplistic models of lost-wax casting. The author emphasizes the variability and adaptability of casting methods employed by ancient artisans.

This article successfully challenges the dominant skepticism surrounding the use of lost-wax casting in pre-Han China by providing compelling evidence that the Met tripod's diatrete ornamentation was likely created using lost-wax techniques. Future research should focus on more detailed analyses of other similar bronze artifacts and further investigation into the intricacies and variations of ancient casting methods.

The study is primarily based on a single artifact, limiting the generalizability of its findings. While the author's analysis is extensive, it relies on visual inspection and interpretation, potentially leaving room for other interpretations. Further experimental replication studies are needed to fully test the proposed lost-wax method.