China’s bizarre 3,000-year-old bronze masks may once have been draped in colored silk, new traces reveal

The bronze masks of Sanxingdui, with their huge protruding eyes and angular faces, look like nothing else from ancient China. A new study now suggests that the bronze we see today is only part of the picture. Researchers found silk residue stuck to the metal, including around the right eye and eyebrow of one large mask, which suggests the faces may once have worn fabric. The team published the work in the journal Antiquity on 26 October 2026.

The pits of Sanxingdui

Sanxingdui lies in Sichuan Province in southwest China and belongs to the ancient Shu civilization. Archaeologists found two major sacrificial pits there in 1986, and between 2019 and 2022 they excavated six more. More than 780 bronzes came out of the first two pits alone, and the pits also held gold, jade and ivory. The finds date to the Late Shang period, about 1300 to 1046 BCE, which makes them roughly 3,000 years old.

What the researchers found

Jianbo Guo, Ruochen Ge, Qiutong Cai, Jingyu Tian and Lu Yang studied textile residues on artifacts from sacrificial pits K2 to K8. The authors come from the Sichuan Provincial Institute of Cultural Relics and Archaeology, Northwest University, the Sanxingdui Museum and Yunnan University. They identified silk on 101 artifacts. Most of them were bronzes: 94 bronze items across 28 types of vessels and objects. Silk also turned up on gold foil, jade implements and ivory fragments.

The team used digital and electron microscopy, infrared spectroscopy and Raman analysis, and these methods let them confirm silk and separate it from animal hair. Bronze corrosion helped the fragile fibers survive. In some cases, corrosion products mineralized the fibers. Heat carbonized other fragments, and a few kept well-preserved fiber structure.

The mask with silk around its eye

One large mask from pit K3, catalogued as K3QW:21, carries three separate patches of silk around its right eyebrow and eye. One patch has an open, gauze-like weave, and the other two are more tightly woven. The researchers say the silk may have covered or decorated the mask. They also stress that nobody can know for certain what the mask looked like when people placed it in the pit.

Some of the silk carried color. The team found red ochre, an iron-rich mineral pigment, on silk fibers, plus a deep-red organic dye whose source they have not identified. They also found calcite that may have served as a surface coating, although its purpose is uncertain. Most of the cloth uses a plain weave, but some pieces show more complex interlacing, and one bronze ornament carried up to five layers of textile.

What the silk was doing in the pits

The location of the silk gives some clues. In pit K3, the silk lay beneath objects, mostly toward the southern and central part of the pit floor. In pit K7, most affected objects had silk on their undersides. The authors argue that silk was in large-scale use at Sanxingdui by the Late Shang period and formed an important part of the site’s sacrificial system alongside bronze, jade and ivory. They suggest it may have worked as a protective layer, a wrapping for ritual items, or an offering in its own right, but the evidence does not settle which.

What remains uncertain

The study cannot say where the silk was made. Spindle whorls and other textile tools at the site hint at local production, and some Sanxingdui samples look as sophisticated as textiles from the Central Plains, but neither point proves local manufacture. The researchers also raise the possibility that perishable silk carried writing or symbols. They found no writing on the fragments they studied, so that idea stays speculative for now.

The paper also places ancient Shu within the wider history of early Chinese silk, and it adds Sichuan to the map of early silk use in China.

Sources: Guo, J., Ge, R., Cai, Q., Tian, J. and Yang, L. (2026), “Silk and sacrifice at Sanxingdui: early evidence of silk use in ancient Shu, south-west China,” Antiquity, doi.org/10.15184/aqy.2026.10448 (open access, CC BY-NC-ND 4.0). Also Arkeonews (Leman Altuntaş, 28 October 2026). Lead image: Sanxingdui bronze mask, Tyg728 / Wikimedia Commons. It is illustrative, and the study did not analyze this mask.