The materials used to produce xylographs are a valuable source to locate time and place of printing. Material analysis is a promising field of research about several aspects of the production of manuscripts and xylographs. Thanks to a collaboration with Dr. Alessandro Boesi, this section is devoted to wood analysis.
In Tibet, printing and technology of the book has always been strongly dependent on wood, which was used for blocks and book covers. Wood identification is a straightforward way to obtain basic information about the origin of the material and the regions supplying it. A variety of wood species are available in different regions of Tibet, whereas other types of wood could be imported from Nepal, India, Bhutan and China.
It is possible to determine the wood species by means of microscopic techniques. This can be done through high-resolution pictures or by observing micro samples of wood taken from extant blocks and covers.
Wood selected for printing blocks requires properties such as hardness, low abrasiveness and structure allowing carvers to obtain high precision in shaping letters and cutting illustrations. At the same time it should have a uniform structure and reduced tendency to crack. A different kind of material used for blocks could likely affect not only the carving process, but also the style of ductus.
A wide range of woods was used for covers, each with different material properties. Birch (སྟག་པ་ཤིང་ stag pa shing, གྲོ་ག་ gro ga) and pine (ཐང་ཤིང་ thang shing, སྒྲོན་མེ་ཤིང་ sgron me shing) were most frequently used. Some kinds of wood had to be cooked several times in liquid butter to prevent them from warping.
Alessandro Boesi has carried out wood analysis of a blockprint from a private collection, as well as of 7 wood covers kept at the Museum of Archaeology and Anthropology in Cambridge. A preliminary report of this investigation will be uploaded soon.