Multi-technique analysis of the mural materials and techniques in the 5th cave of the five temple grottoes in Subei, China

As part of the Dunhuang grottoes, the Five Temple Grottoes are notable for their overlapping mural structures, painted over multiple dynasties, offering valuable insights into Dunhuang's cultural and artistic evolution. However, due to historical changes and both human and natural impacts, Cave 5 is in poor condition, with various mural diseases. Research on the materials and techniques used in the Five Temple Grottoes is limited. In this study, we employed polarizing microscopy, laser particle size analysis, FT-IR, XRD, and SEM-EDX to analyze the materials and techniques of the collapsed murals in Cave 5. Results showed that Cave 5 murals consist of multiple layers, including clay texture pillars and paint layers. The Northern Zhou Dynasty murals used hematite, calcite, muscovite, and talc, reflecting techniques similar to the Mogao Grottoes. The Northern Song Dynasty murals incorporated hematite, azurite, chlorite, calcite, and gypsum. Additionally, clay in the Northern Zhou Dynasty murals had smaller particle sizes but higher clay content. The use of straw fiber in the Northern Zhou Dynasty murals contrasts with the flax fiber used in the Northern Song Dynasty murals. This study aims to understand the artistic materials and technological characteristics of the murals in Cave 5 and to provide scientific support for their protection and restoration.