Despite increasing digitalization, a world without paper is unimaginable. A large part of mankind’s cultural heritage would not have survived without paper. The restoration of this fragile organic material is therefore of great importance. In Japan, people no longer use modern filler paper, but instead analyze the original paper and produce it by hand based on the results. Masaki Utsunomiya, Ph.D., from the University of Nara researched the theory and practice of this technique in his dissertation: it is called sukibame and has been continuously developed since 1998
Application of the Sukibame technique
Original document after restoration
Chamfering is a mechanical process that allows the restoration of large quantities of paper in a short time. This technique was developed in Europe, where paper is traditionally made from fine-fiber cotton or short-fiber wood pulp. During paper restoration, imperfections are filled with a fiber suspension. This method has been used in Europe since the beginning of the 20th century. This technique was also used for many books in Japan, where, in addition to replacing missing pieces of paper after restoration, a backing paper was usually attached to the reverse side. Unlike in Europe, mulberry bast, whose fibers are long and thick, was used extensively for paper production in Japan. The scientific study of old paper documents has shown a rapid development since around the year 2000. At the same time, the view prevailed that one of the aims of paper restoration should be to preserve the texture typical of Japanese paper in addition to repairing defects. However, if a backing paper is used, this changes the entire texture of the document, for example by altering the hardness.
The European method, in which defects would be replaced by new mulberry fibers, does not show satisfactory results here. In order to achieve textural equality between old and new material, a technique is required in which as much of the fibers as possible can do without backing paper and new material is used exclusively to fill defects. Together with Akinori Ogawa (Kochi Prefectural Paper Factory, formerly Kochi Prefectural Industrial Paper Technique Center), Tokuichi Taguro (Shubi Co., Ltd.) developed a new form of sukibame technique. Her attention was focused on a Japanese papermaking technique called Nagashizuki, in which the fibers are loosened during washing. With this technique, it is possible to produce restoration paper from long fibers such as those of the mulberry tree and at the same time rinse away excess fibers from all undamaged areas. This method, which was developed independently in Japan, is known as nagashi suki sukibame. Today, the majority of historical paper documents are restored using nagashi suki sukibame, shortened here to sukibame. The sukibame technique is mainly used for large quantities of mulberry paper, and its greatest advantage is the short time required.
You can read how sukibame was used for the restoration of paper documents from the Ii clan in Hikone in RESTAURO issue 2/2019 . You can also read the full article digitally as an ePaper.