Multi-Analytical Study on the Architectural Polychrome Paintings of the Qing Dynasty in Bozhou, China

Polychrome painting, a defining decorative element of ancient Chinese wooden architecture, served both esthetic and protective purposes. During the Qing Dynasty, it was categorized into official and folk styles, with the latter characterized by greater flexibility and regional diversity, forming a distinct artistic tradition. This study focuses on the Bozhou theatrical stage, a National Key Cultural Relics Protection Unit that exemplifies the fusion of regional architectural traditions that combining Huizhou-style gable walls with a northern-style glazed tile roof. On-site assessment identified various forms of deterioration in the polychrome paintings, underscoring the need for material analysis to inform conservation. Integrating with multi-analytical techniques of OM, SEM-EDS, Raman, XRD, FT-IR, and THM-Py-GC/MS, the research reveals that the structure was built primarily from locally sourced Populus wood. The painting ground layer was prepared using traditional techniques such as Yima-Wuhui and Danpihui, with brick ash as the base material, reinforced by bast fibers and bound with organic additives including fermented animal blood, animal glue, and tung oil, reflecting the adaptation of official methods into folk practice. Pigment analysis distinguished between original mineral-based paints and later synthetic pigments, separating original work from subsequent documented and undocumented repainting. The detection of imported synthetic pigments further illustrates the material and cultural exchanges of the late Qing period. By clarifying material use and technical practices, this study advances the understanding of Qing folk architectural painting and provides a scientific basis for its ongoing conservation and restoration.