Journal of Archaeological Science: Reports 17 (2018) 529–537 Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep Analytical investigation into materials and technique: Carved lacquer T decorated panel from Fuwangge in the Forbidden City of Qianlong Period, Qing Dynasty Na Wang, Tong Zhang, Junrong Min, Guanghua Li, Yinzhong Ding, Jianyu Liu, An Gu, ⁎ Baoqiang Kang, Yuan Li, Yong Lei Department of Conservation Science, The Palace Museum, Beijing 100009, China ARTICLE INFO ABSTRACT Keywords: Carved lacquer is a kind of distinctive Chinese traditional handicraft. However, there are few researches on its Carved lacquer scientific investigation. Since carved lacquer has developed to its peak in Qianlong Period (1736–1796 CE) of the Chinese lacquer Qing Dynasty (1636–1912 CE), a typical carved lacquer object of this period collected from the decorated panel Boiled tung oil of Fuwangge (Belvedere of Viewing Achievements) in the Forbidden City, has been analyzed by complementary Porcine blood techniques to investigate its materials and technique. Morphology observation and dimension survey of the cross Py-GC/MS section of carved lacquer object were achieved through laser scanning confocal microscope. Pigments and other Brick powder inorganic materials were identified by the combination of polarized light microscopy, Raman spectroscopy, X- ray diffraction, scanning electron microscopy, as well as thermogravimetric analysis and differential scanning calorimetry, meanwhile, pyrolysis coupled with gas chromatography/mass spectrometry was carried out to identify organic materials. Analytical results indicated that the investigated carved lacquer object was consisted by three layers, including mortar layer, carved yellow lacquer layer in the middle and carved red lacquer layer in the surface. In mortar layer, brick powder was served as aggregate, the mixture of boiled tung oil and porcine blood might be used as binding media. Yellow pigment of orpiment and red pigment of cinnabar were confirmed as coloring material in carved yellow and red lacquer layer respectively, in addition, mixture of Chinese lacquer and boiled tung oil was applied as main materials in both carved yellow and red lacquer layers. Materials used in the carved lacquer object of decorated panel of Fuwangge was consistent with the historical recipe about carved lacquer in Qing Dynasty. The present research could not only be served as a scientific recovering of Chinese traditional carved lacquer technique in Qianlong Period of Qing Dynasty, but also can contributed to the con- servation and restoration of carved lacquer decorated panel of Fuwangge in the Forbidden City. 1. Introduction Just as its name, carved lacquer is made by brushing lacquer sap on objects to get a film thick enough for carving, and then carving the Lacquer, the oldest natural resin coating and native to Asian region, patterns. According to different color, there are carved red, yellow, is first discovered and used in China. Chinese people have manu- green, black and polychromic lacquer, while carved red lacquer is the factured and utilized lacquer objects since the Neolithic Age. The oldest most popular one (Li, 1989; Ni, 2009; Zhang, 2010).Carved lacquer is lacquer object found in China is a wood bowl painted by red lacquer honored as one of the most noble lacquer object because of its excep- from Hemudu Site > 7000 years ago in Zhejiang Province (Ni, 2009). tional beauty and exquisite workmanship. Owing to its unique aes- Like ceramics, bronze, jade, lacquer objects has an important and thetic, historical and cultural connotations, carved lacquer has been practical significance in Chinese arts and crafts history. There are ele- listed in the first batch of catalogue of nationally protected immaterial gant lacquer objects in each dynasty of ancient China, such as lacquered cultural heritage in 2006. tableware, furniture, coffin, and lots of lacquered artworks. According to historical documents, carved lacquer appeared as early Usually, lacquer is applied as coating on objects, however, carved as Tang Dynasty (618–907 CE), and increasingly developed during the lacquer is the only one which introducing sculpture into lacquer objects following Song (960–1279), Yuan (1271–1368 CE), Ming making process and expresses its beauty by three-dimensional form. (1368–1644 CE), Qing (1636–1912 CE) Dynasties, especially in Ming ⁎ Corresponding author. E-mail address: [email protected] (Y. Lei). https://doi.org/10.1016/j.jasrep.2017.12.023 Received 12 October 2017; Received in revised form 30 November 2017; Accepted 8 December 2017 Available online 20 December 2017 2352-409X/ © 2017 Elsevier Ltd. All rights reserved. N. Wang et al. Journal of Archaeological Science: Reports 17 (2018) 529–537 Fig. 1. Fuwangge in the Forbidden City (a) and decorated panel of the belvedere decorated by carved lacquer (b). and Qing Dynasties, carved lacquer is much appreciated by the royal DSC) could study thermodynamic changes in materials processes (Pérez family. In Qing Dynasty, carved lacquer has developed to its peak in et al., 2016), therefore, in the present work these techniques have been Qianlong Period (1736–1796 CE) for two reasons, on one hand, this complementarily used to investigate pigments and other inorganic kind of exquisite and complicate artwork is one of Emperor Qian long's materials in the carved lacquer object. favorite, one the other hand, Qianlong Period is abundant in materials Lacquer is the principal raw material for making carved lacquer, and affordable for the heavy use of Chinese lacquer which is expensive. due to its excellent solvent resistance and corrosion resistance, up to A huge number of carved lacquer objects have been manufactured in now, no solvent can solve or hydrolyze lacquer film, thus just the this period and stored in The Forbidden City nowadays. In the present techniques which can provide information for solid organic materials search, a typical Qianlong Period carved lacquer object was collected are suitable for lacquer analysis. Pyrolysis coupled with gas chroma- from the decorated panel of Fuwangge (Belvedere of Viewing tography/mass spectrometry (Py-GC/MS), in which macromolecules Achievements) in the Forbidden City and to be researched. are thermally cracked into small molecules and then separated by GC As a kind of traditional and complicated handicraft, written records and detected by MS, has been shown to be the most efficient technique is necessary for the development and handing down of lacquer objects, for lacquer analysis and greatly promoted the study of lacquer (Le Hô but in feudal China, literati and officialdom, who in charge of the et al., 2012; Niimura, 2009; Sung et al., 2016). Since the main com- cultural tools, almost paid no attention to the manufacture of lacquer position of lacquer is catechol derivatives (Niimura, 2009), which objects, because in their opinion it is just a kind of hand-made work, contains polar phenolic hydroxyl groups in its molecular structure and thus resulting in that there are not too much historical records about might give rise to excessive interactions with gas chromatographic lacquer has been spread up to now (Li, 1989; Ni, 2009). The only ex- column and result in peak broadening and the loss of resolution, it is isting monograph about lacquering techniques is Xiushilu (Records of necessary to derivatize the phenolic hydroxyl group to improve its lacquering) written by Huang Cheng in Ming Dynasty. Although the volatility and stability during analysis, therefore, on-line methylated records about carved lacquer in Xiushilu has laid the foundation for its Py-GC/MS technique has been performed in the present work with the study, they are so brief that nowadays we can't completely understand help of tetramethyl ammonium hydroxide (TMAH) to convert all the the raw materials and techniques applied for making carved lacquer. hydroxyl-containing components in tested sample into their methyl Furthermore, publications about carved lacquer mainly focus on the ethers to facility the identification of lacquer and other polar organic collection and appreciation in recent years, and the available scientific materials in the tested carved lacquer sample (Challinor, 2001). research about lacquer objects is usually about excavated relics but not the handed down ones (Wei et al., 2011; Yuasa et al., 2015), which results that there is little scientific publications referring to the com- 2. Material and methods positions or technology of carved lacquer. Scientific research of carved lacquer has an important significance 2.1. Historical carved lacquer sample to the development of Chinese and world's art history. In consideration of the complex of carved lacquer, no analytical technique alone would Fuwangge locates in the fourth courtyard of the Qianlong Garden even close to solve all the problems, complementary analytical methods (Garden of the Palace of Tranquil Longevity) in the Forbidden City would be necessary to investigate the materials and technique used in (Fig. 1-a), and built in the thirty-seventh year (1772 CE) of Qianlong the carved lacquer object collected from the decorated panel of Period in Qing Dynasty, as shown in Fig. 1-b, panel of Fuwangge was Fuwangge in the Forbidden City. decorated by carved red lacquer. The investigated sample in the present Since thickness of the tested sample is > 3 mm, laser scanning work is a piece of carved red lacquer collected from the decorated