清代绿色蟠龙邮票印刷材料无损分析

A Non-Destructive Study of Printing Materials of an Imperial China Green Engraved Coiling Dragon Stamp

利用超景深三维视频显微镜,激光显微共聚焦拉曼光谱仪和扫描电镜-能谱仪对一张清代绿色蟠龙邮票样品的纸张,油墨等印刷材料进行无损分析。结果表明,该样票采用手工雕刻凹版印刷,所用承印物为长纤维机制纸,未经过涂布,无水印,背胶;纸张填料中含有Al,Si等元素,推断纸张填料可能是高岭土(Al_2O_3·2SiO_2·2H_2O)之类的物质。绿色油墨包含了蓝色普鲁士蓝(Prussian Blue,Fe_4[Fe(CN)_6]_3·14-16H_2O)和黄色铬酸铅[Lead(Ⅱ)chromate,PbCrO_4]颜料,根据印刷色彩学色料减色和色光加色理论分析,邮票样品呈现的绿色是由蓝色颜料普鲁士蓝和黄色颜料铬酸铅混合呈色的结果;油墨填料中含有Na,Mg,S,Cl,K,Ca,V,Zn,Ba等元素,推断油墨填料为MgCO_3,CaCO_3,BaSO_4等物质。上述三项技术联用,在邮票等纸质品的无损分析中具有广阔的应用前景。

Non-destructive measurement methods including video microscopy （VM）,Raman spectrometer （RS）,and scanning electron microscopy-energy dispersive spectroscopy （SEM-EDS）were employed to analyze the printing materials of a green curled-up dragon stamp sample from the late Qing Dynasty in terms of the paper and ink.The results indicated that the plate-making process of the sample belonged to handcrafted gravure while the slender and dense paper fiber with no coating,water-mark,or gumming.Elements of Al and Si were inspected in fillers of paper,therefore,it could be inferred that kaolin （Al2 O3 · 2SiO2·2H2O）wasthefillerofpaper.GreeninkwasmadeupofbluepigmentPrussianBlue（Fe4[Fe（CN）6]3·14-16H2O）and yellow pigment Lead（II）chromate（PbCrO4 ）.According to theories of additive color and subtractive color,ink presented green color due to the effect of Prussian blue and Lead chromate mixed together.Elements of Na,Mg,S,Cl,K,Ca,V,Zn and Ba were measured from fillers of the ink and it could be inferred that MgCO3 ,BaSO4 ,CaCO3 and other substances might be con-tained in ink fillers.This study with three techniques mentioned above is viable and it has a broad application in non-destructive analysis of printing and paper-based artwork.