Characterization of a 13th-century Tibetan birch bark manuscripts: investigating utilization and craftmanship

Paper has become the world’s predominant writing medium since its invention. However, non-paper writing materials have also played a significant role in human civilization, serving purposes beyond mere text transmission. Despite their importance, research about craftmanship and utilization of these alternative materials remain limited. In this study, we employed non-destructive and micro-destructive analytical techniques—including THM-Py-GC/MS, p-XRF, ATR-FTIR, and hyperspectral imaging (HIS) to examine fragments excavated from Taklung Monastery in Tibet. Results identified birch bark as the writing material and revealed that ink was prominently gold (Au). This discovery reports a rare case of the utilization of gold ink on birch bark, offering valuable insights into 13th-century Tibetan writing material production. Furthermore, HIS enabled text extraction from the fragments. Combined with the unique excavation context, we suggest that birch bark also possesses religious significance. This study enhances our understanding of the diverse applications of writing materials of ancient Tibet.