确认古纸涂布层及涂料的无损新方法

New Approach for Non-Destructive Investigation of the Coated Ancient Chinese Papers

关键词:  手工纸  扫描CT  涂布  拉曼光谱  铅白

Key Words:handmade Chinese papers  micro-CT  coating  Raman spectroscopy  lead white

摘要:涂布是由中国人最早发明的纸张加工技术之一，是中国造纸术的重要组成部分，也是印刷技术得以推广的关键。通常认为，早至公元3到4世纪，中国已经使用涂布技术改进纸张的外观和性能。以往研究中，对古纸中涂布层和涂料的判断主要依赖显微镜观察和表面元素分析，始终欠缺准确、精确的研究手段和判断依据。将计算机显微断层扫描技术（Micro-Computed Tomography，简称扫描CT）和拉曼光谱首次联合，应用于清代和近现代手工纸，准确甄别出涂布纸以及涂料种类。该方法完全无损，结果准确，为手工纸涂布工艺研究开拓新思路。

Abstract:China is the country that first applied coating pigments onto papers. Coating became then an important component of Chinese papermaking and also a key to the widespread of printing technologies. Conventionally, it is believed that Chinese papermakers back in the third to the fourth century AD had already started using coating pigments to improve the appearance and physical properties of handmade papers. To identify whether or not a coating pigment was used on ancient Chinese papers, previous research relied on microscopic examination and surface elemental analysis, which usually produced informative but inconclusive results. The present research, for the first time, applied jointly Micro-Computed Tomography (micro-CT) and Raman spectroscopy to the samples of both ancient and modern handmade Chinese papers, which not only distinguished the coated papers from the uncoated ones but also identified the coating pigment applied on the paper. The new methodology established here is completely non-destructive and can produce scientifically conclusive results, which offers new insights into the study of ancient coated, handmade Chinese papers.