Multi-analytical study of the ancient Khan-Geum (韓錦) silk brocade excavated from the Taklamakan Desert

This study employed a multi-analytical approach—accelerator mass spectrometry (AMS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD)—to investigate the manufacturing technology and material characteristics of the Khan-Geum (韓錦) brocade excavated from the Taklamakan Desert. AMS radiocarbon dating places the brocade in the 1st–2nd century AD. FT-IR and XRD together identify a β-sheet-rich fibroin (crystallinity index ≈ 51%, above that of a modern reference silk measured under identical conditions), indicating that the disordered amorphous regions were preferentially lost while the ordered β-sheet core was retained—a selective, amorphous-first degradation rather than wholesale preservation or advanced breakdown. SEM and cross-sectional measurements reveal a bimodal distribution of fiber circularity and cross-sectional area, a variability that suggests a mixture of raw silk types rather than a single uniform stock, with partial degumming that preserved sericin as a cohesive sizing agent for untwisted yarns. Structural analysis classifies the textile as a quadruple warp-faced compound tabby of exceptionally high density (174 ends/cm, 24 picks/cm; warp-to-weft ratio 7.3:1). The divided-warp mechanism enabled five-color patterning within a four-layer matrix, indicating sophisticated heddle control. Triangular borders and localized lacquer residues reinforced the selvedge and protected the textile surface. These findings establish the Khan-Geum as a technological benchmark for early high-density warp-faced silk brocades. The integration of zoomorphic and cloud motifs, together with a woven inscription containing the ethnonym 韓 (Khan), suggests the use of a sophisticated multi-heddle and multi-treadle horizontal loom capable of producing highly detailed, non-linear patterns at extreme warp densities. Collectively, these findings indicate that the brocade was produced within a highly developed warp-faced weaving tradition of the eastern Silk Road, reflecting a refined synthesis of fiber selection, structural design, and symbolic expression.