弦歌台大成殿文物建筑彩绘颜料成分分析

Analysis of the pigment composition of the cultural relic architectureof Dacheng Hall in Xiange Tai

弦歌台又被称为绝粮祠,整体布局以中轴线为中心呈现东西对称,现存建筑的规制为三进院落,从南向北依次为正门、戟门、大成殿、弦歌书院。大成殿作为弦歌台最核心的建筑,外观气势宏伟,彩绘精美绝伦,是我国东部地区规格较高的孔庙建筑之一。弦歌台大成殿在自然环境和人为因素的长期影响下,彩绘表面出现了褪色、龟裂、颜料脱落等多种病害,彩绘修复工作已成为当前文物保护亟待解决的棘手问题。本工作对彩绘样本的层位和形制进行详细分析,从剖面和表面等多角度进行全面研究,发现大部分彩绘样本由内向外的结构依次为基底层、地仗层、颜料层,蓝色彩绘样本所使用的地仗层为传统的单披灰工艺,与之不同的是红色彩绘样本为无地仗彩绘,红色颜料层直接绘制于基底层上,推测这可能与时代的发展及工艺的变化有关。为了更好地服务文物进行科学保护,需要了解大成殿彩绘颜料成分及制作工艺等。采用超景深微观分析、扫描电镜及能谱仪分析、显微拉曼光谱分析等现代技术及方法,对彩绘颜料样本进行了层位结构、微观及成分检测分析。结果表明,在制作工艺上,大成殿彩绘颜料层剖面多为两层以上叠加,是明显的重层彩绘,说明历史上至少经历过两次以上重绘。同时发现大成殿彩绘颜料层既有重做彩绘,又有以一种颜料打底使用另外一种颜料盖面的彩绘工艺;红色颜料推定为赤铁矿,蓝色颜料推定为天然群青和人工合成群青,部分彩绘使用过近现代颜料。地仗层采用方解石为主的单披灰工艺。此外,通过研究后还发现彩绘样本颜料层厚度不一,部分颜料表面出现不同程度的脱落。因此,在后续对病害修复时所使用的修复材料、清洗和加固方法还需要继续深入研究。研究结果为弦歌台大成殿的彩绘颜料鉴定、修复材料选择提供了关键信息,为后期彩绘保护工作的开展提供科学依据,避免了彩绘文物出现“保护性破坏”等问题。

The overall layout of Xiange Tai(also known as Jueliang Ci)is symmetrical from the east to the west on the central axis,and the existing buildings are regulated as a three-entry courtyard,with the main gate,the halberd gate,Dacheng Hall,and Xiange Study Hall in turn from the south to the north.Dacheng Hall,as the most central building of Xiange Tai,boasting a magnificent appearance and beautiful colored drawings,has a width of seven rooms and a depth of five rooms,and is a single-eaved hiatus style building.Green glazed tiles covering the roof,corridors around and 24 square pillars of green stone supporting are the distinctive features of Dacheng Hall,which is unique among the Confucius Temples in China.Under the long-term influence of the natural environment and human factors,the painted surface of Dacheng Hall has suffered from a series of diseases such as color fading,cracking,pigment falling off,etc.The painting restoration work has become a prominent problem that needs to be solved for the current conservation of the cultural relics.We analyzed the layers and forms of the painted samples in detail,and conducted a comprehensive study from multiple angles,including the profile and surface,to find that 1)most of the painted samples consisted of the base layer,plaster layer and pigment layer in sequence from the inside out;2)the plaster layer of the blue samples was made via the traditional single-layer plastering process;3)the red samples had no plaster layer—the red pigment was painted directly on the base layer.It is speculated that this may have something to do with the development of the times and the changes in the craftsmanship.In order to better serve the scientific conservation of the cultural relics,it is necessary to understand the pigment composition and production process of color paintings of Dacheng Hall.In this study,modern technologies and methods such as super depth-of-field 3D microscopy,scanning electron microscopy-energy dispersive spectrometry and Raman spectrometry were used to analyze the layer structures,microscopic forms and compositions of the pigment samples.According to the profile observation results,the pigment layer of Dacheng Hall had more than two sub-layers,indicating that it had been repainted in history.Besides repainting,we also found the painting process of using one pigment(as the surface)covering another pigment(as the base).In terms of pigment materials,the red one was hematite,the blue ones were natural ultramarine and synthetic ultramarine and modern pigments were used for parts of the paintings.The plaster layer was mainly made via the calcite-based single-layer plastering process.In addition,it was also found that the thickness of the pigment layer of the painted samples varied from one another,and that falling off to different degrees appeared on some pigment surfaces.Therefore,the repair materials,cleaning and reinforcement methods used in the subsequent restoration need to be further studied.The results of the study provide key information for the identification of pigments and the selection of repair materials for Dacheng Hall and provide a scientific basis for the following conservation of painted cultural relics,avoiding problems such as“protective damages”.