The Getty Conservation Institute, in collaboration with the Chengde Cultural Heritage Bureau and the Hebei Province Cultural Heritage Bureau, is developing an approach to the conservation of architectural decorative painting as a component of the application of the Principles for the Conservation of Heritage Sites in China, guidelines for the conservation and management of cultural heritage sites developed by Chinese national authorities in partnership with the GCI and the Australian Department of the Environment and Heritage.

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The selected site, Shuxiang Temple, is the only largely unrestored temple among eight remaining Buddhist temples at the Imperial Mountain Resort of the Qing dynasty emperors, a UNESCO World Heritage Site, in the city of Chengde in northeast China. Shuxiang Temple is a classic Han-style temple complex built in 1774 by the Emperor Qianlong. After decades of neglect, only two buildings of an original twenty-two—the main structure, Huicheng Hall, and the gatehouse—retain both structural and decorative historic fabric. In particular, these two buildings preserve a significant amount of traditional polychrome painted decoration. This painting, typical of decoration on imperial wooden architecture of the period, consists of plaster and fiber applied to the timber in multiple layers to provide a smooth surface for the application of paint. Applied on exterior and interior surfaces, it served both to decorate the building and to protect wooden beams and elements against moisture and pests. Prominent architectural features below the roof eaves were decorated with colorful patterns and motifs that followed strict design standards denoting the official rank and function of a building.

These paintings, now much deteriorated, are a rare example of surviving mid-Qing architectural painted decoration at Chengde, where repainting has historically been the most commonly employed treatment. The conservation of historic painted surfaces on wooden architecture is a relatively new field in China; previously, little research and testing on appropriate materials and methods of treatment had been undertaken.

In 2005, working with colleagues from the China National Institute of Cultural Property (CNICP), the GCI began to address these needs with research and testing at Shuxiang Temple. To better understand the technology of these paintings and their susceptibility to deterioration processes, a condition assessment and analytical investigation of the paintings, including study of the traditional craft with a master craftsman, were undertaken. This process included both a literature review and detailed investigation of the youman-based plaster and hemp fiber stratigraphy of the painting (youman, a traditional binder for the plaster, contains wheat flour, limewater, and cooked tung oil).

The treatment methodology included both stabilizing the paintings and implementing preventive measures to slow deterioration. Treatment testing involved evaluating a range of traditional and modern materials, developing methods for treatment application, and determining the sequencing of interventions. Investigation began on painting fragments, followed by in situ testing, which led to the completion of demonstration areas on both the exterior and interior painting of Huicheng Hall. Laboratory testing and accelerated aging tests were also carried out at the GCI and the CNICP. Tests were documented and monitored, and evaluation procedures were developed in order to assess the working properties and performance characteristics of treatments over time. Treatment testing and design involved an interdisciplinary team of conservators, scientists, and craftsmen. This culminated in an internal experts review meeting in May 2007 with representatives from Chengde Cultural Heritage Bureau and Hebei Province Cultural Heritage Bureau. The conservation approach and results to date were favorably evaluated, and preparation of an implementation plan for the historic architectural paint at Shuxiang Temple is now under way.