Buddha from Vat Kampong Loung: Background and materials analysis
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The seated Buddha from Vat Kompong Loung (a pagoda in Angkor Borei District, south of Phnom Penh), now on display at the National Museum of Cambodia is believed to date back to the 7th or 8th century. Originally carved from grey/green, fine grained sandstone, the sculpture had been painted and repainted several times throughout its history and use as a religious icon. Along with the application of paint, alterations and additions had been made to the sculpture, significantly modifying the appearance of the figure. These alterations became apparent during conservation treatment in the early 2000’s, in which museum conservators began to remove exterior synthetic paint layers. The alterations included repairs to the proper right hand, fashioned from copper-alloy and wooden elements, as well as alterations of the usnisa and proper left knee using a repair mortar. These additions were removed, along with synthetic paint and gilding layers, in order to reveal the original form of the sculpture.
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Image: Metropolitan Museum of Art
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The final appearance, shown in the image above, reveals the sandstone, still covered in places with a dark coating, presumably lacquer. Remnants of red and gold were also visible throughout. At the back of the proper right thigh a large square patch remains, where some gold and red layers were intentionally preserved.
During treatment, conservators at the museum attempted to characterize the stratigraphy of paint layers and the repair materials using visual identification supplemented with knowledge of traditional methods. Layers of polychromy were classified as gold synthetic paint, gold leaf, red lacquer, and black lacquer. The lacquers are likely of vegetal origin, colored with added pigments, although their exact composition was unknown. The repair mortar was thought to be created from a mixture of ground mussel shells, palm juice and rice starch.
During my internship at the National Museum, I sampled areas of polychromy from repair elements, remaining lacquer on the stone sculpture itself, and the repair mortar. I brought these samples back to UCLA, and analyzed them using SEM/EDS, μ-Raman spectroscopy, and ATR-FTIR in order to obtain a better understanding of the materials present. Cinnabar was identified as the red pigment present in red lacquer layers both on the surface of the stone, as well as repair elements. No added pigment included within the black lacquer layers. The repair mortar was found to contain crushed rock fragments, quartz, fragments of diatoms (possibly from diatomaceous earth), and rice starch. Collaboration with scientists at the Getty Conservation Institute allowed for analysis of lacquer layers using pyrolysis gas chromatography-mass spectrometry. Both red and black lacquers were found to be thitsi lacquers, however differences in composition were observed between various lacquering campaigns and colors (red vs black). This is likely due to the presence of different additives mixed in with the lacquer. Further research and comparison to historical Cambodian lacquering practices may aid in dating the application of the lacquer layers.
During treatment, conservators at the museum attempted to characterize the stratigraphy of paint layers and the repair materials using visual identification supplemented with knowledge of traditional methods. Layers of polychromy were classified as gold synthetic paint, gold leaf, red lacquer, and black lacquer. The lacquers are likely of vegetal origin, colored with added pigments, although their exact composition was unknown. The repair mortar was thought to be created from a mixture of ground mussel shells, palm juice and rice starch.
During my internship at the National Museum, I sampled areas of polychromy from repair elements, remaining lacquer on the stone sculpture itself, and the repair mortar. I brought these samples back to UCLA, and analyzed them using SEM/EDS, μ-Raman spectroscopy, and ATR-FTIR in order to obtain a better understanding of the materials present. Cinnabar was identified as the red pigment present in red lacquer layers both on the surface of the stone, as well as repair elements. No added pigment included within the black lacquer layers. The repair mortar was found to contain crushed rock fragments, quartz, fragments of diatoms (possibly from diatomaceous earth), and rice starch. Collaboration with scientists at the Getty Conservation Institute allowed for analysis of lacquer layers using pyrolysis gas chromatography-mass spectrometry. Both red and black lacquers were found to be thitsi lacquers, however differences in composition were observed between various lacquering campaigns and colors (red vs black). This is likely due to the presence of different additives mixed in with the lacquer. Further research and comparison to historical Cambodian lacquering practices may aid in dating the application of the lacquer layers.