Biological issues in the conservation of mural paintings of Takamatsuzuka and Kitora tumuli in Japan

This article introduces the background history to the detailed microbial analysis in the following paper by Sugiyama et al. in this book. Takamatsuzuka and Kitora tumuli located in Nara prefecture were both constructed between the 7th and 8th centuries during the so-called `big tomb' period. Both tumuli are famous for their beautiful mural paintings that were drawn directly on thin wall plaster in the stone chambers. Both the Takamatsuzuka and Kitora tumuli were designated as special historic sites, and Takamatsuzuka's mural paintings were designated as a national treasure. However, biological issues arose in the conservation of the mural paintings. Through an exchange of information between France and Japan, commonalities between the situations of the paintings of the Takamatsuzuka and Lascaux cave have been identified. In both cases, the paintings have existed in buried environments for a long time with a damp internal atmosphere. Since both mural paintings had historically been subjected to high humidity, it was feared that if the paintings were kept in a dry condition on site, they could peel off and this would be a catastrophe. Beyond the difference in the ages of the Takamatsuzuka and Lascaux murals, an important difference between the Takamatsuzuka and the Lascaux paintings is their relative size. The Takamatsuzuka site is very small. The stone chamber is roughly 1.0 m wide, 2.7 m deep, and 1.1 m in height, which makes it a difficult place to work. A third difference is that the support layers of the paintings and pigments in Takamatsuzuka are also different from those in Lascaux. The chamber of Takamatsuzuka is constructed of rectangular stones of volcanic tuff. A very thin layer of plaster was applied over the inside surface, and the pictures were Biological issues in the conservation of mural paintings of Takamatsuzuka and Kitora tumuli in Japan