Research on changes in coloring of historic buildings

通过对宫城县至鹿儿岛县31座建于7世纪至8世纪的古寺庙出土屋面瓦片上的颜料分析，讨论了日本历史建筑的外观。当木结构构件被涂上涂层时，这些颜料被认为已经附着在瓷砖上。因此，它们反映了建筑物的颜色。分析结果表明，这些色素只含有铁，不含汞和铅。因此，被涂上朱红或铅红的古寺庙修复模型的颜色与原来的不真实，至少在调查的31座寺庙中是这样。这些寺庙实际上是用铁红着色的，与现有的模型相比，外观相当朴素。在9世纪以后的建筑物中检测到鲜艳的红色，而在10世纪或11世纪以后才观察到朱红的着色。铅红是19世纪以后寺庙和神社最常用的颜料，只有16世纪以后的建筑物才能检测到铅红。这些结果表明，建筑物的颜色受其年龄的影响很大，外观也有变化。此外，还对用于涂装历史建筑的其他颜色颜料进行了调查。其中，钴玻璃颜料的使用值得注意。在没有分析的情况下，用于历史建筑着色的蓝色颜料被认为只有天青石和铜颜料。然而，17世纪以后，在德川行光支持的特殊建筑上发现了不少使用smalt的案例。因此，在讨论一些历史建筑的原貌时，不仅要对它们的红色图像进行修改，而且要对它们的蓝色图像进行修改。

Appearances of historic buildings in Japan was discussed based on the analyses of pigments on excavated roofing tiles at 31 ancient temples built between the 7th and 8th centuries located from Miyagi Prefecture to Kagoshima Prefecture. Those pigments are considered to have become attached onto the tiles when wooden structural members were coated. Accordingly, they reflect the color of the buildings. As a result of analyses, it was found that such pigments contain only Fe, neither Hg nor Pb. Therefore, the colors of restored models of ancient temples coated with vermilion or lead red are not true to the original at least at the 31 surveyed temples. Those temples were actually colored with iron red and the appearances were rather sober compared with existing models. Vivid red pigments were detected from buildings after 9^<th> century, and coloring with vermilion was observed only after 10^<th> or 11^<th> century. Lead red which is the most popular pigment for coloring of temples and shrines after 19^<th> century was detected only buildings after 16^<th> century. These results show that coloring of buildings have had variations strongly influenced by their ages and the appearances have also had variations. Moreover, other color pigments for coating historic buildings were also surveyed. Among them, the use of smalt, Co glass pigment, is notable. Blue pigment for coloring of historic buildings has been believed to be only azurite, Cu pigment, without analyses. However, not a few cases using smalt were detected after 17^<th> century on special buildings supported by Tokugawa Iemitsu. Therefore, not only red but also blue color image of some historic buildings must be revised, when discussing their original appearances.