Scientific Study on Historical Polychrome Objects

与日本和德国的科学家、艺术史学家和修复者合作，研究了历史多色的材料和技术。为了这项研究，我们每年都访问每个国家的研究中心和实验室。虽然中世纪的彩色雕塑主要是在德国进行研究，但在日本，包括绘画，雕塑和建筑物在内的各种彩色物体都进行了研究，因为彩色可以用几乎相同的技术和材料来完成日本物体。由于在日本很难获得从物体上取样的许可，我们没有采用使用截面的分析方法我们开发了一种新的非破坏性分析仪：便携式X射线荧光光谱仪（XRF）。用这种便携式X射线荧光光谱仪对许多彩色物体进行了检测，得到了许多有趣的结果。其中一个例子是分析了一件非常著名的国宝《源氏物语》卷轴画中使用的颜料。便携式XRF被带到博物馆，以避免移动卷轴的各种风险。分析表明，这幅画中使用了4种白色颜料。第一个样品主要含Pb，第二个样品含Ca，第三个样品含Hg，均未检出，第四个样品未检出重元素。这些结果引起了艺术史学家们的一场有趣的讨论。

Materials and techniques for historical polychromy were studied with the collaboration of scientists, art historians and restorers in Japan and Germany. For the study we visited mutually sites and laboratories in each country every year. While mediaeval polychrome sculptures were mainly examined in Germany, all kinds of polychrome objects including paintings, sculptures and buildings were studied in Japan because the polychromy may be done with almost the same technique and materials for Japanese objects. Since it was usually difficult to get a permission of taking a sample from objects in Japan, we did not adopt an analysis by using a cross section We developed a new non-destructive analyzer : a portable X-ray fluorescence spectrometer (XRF). Many polychrome objects were examined with this portable XRF and many interesting results were obtained. One of the examples was the analysis of pigments used in the scroll paintings of the tale of Genji, a very famous national treasure. The portable XRF was brought to the museum to avoid various risks by moving the scroll. The analysis revealed 4 kinds of white pigments were used in the painting. The first one contained mainly Pb, the second one Ca and the third one Hg which did not have ever been found. No heavy elements were detected from the forth one. These results arose an interesting discussion to art historians.cross section.