Home > Publications > NDL Newsletter > No. 204, February 2016

National Diet Library Newsletter

No. 204, February 2016

Japanese paper in action!! : Conservation treatments using "Washi" (2)

Preservation Division
Acquisitions and Bibliography Department

This article is a translation of the article in Japanese
in NDL Monthly Bulletin No. 654 (October 2015).


1. Introduction

In the last issue of the National Diet Library (NDL) Newsletter published in December 2015, we introduced the features of Japanese paper, or washi (和紙), and how it is used for repairing books with Japanese-style binding. In this article, we will give a further insight into the ways of using washi to repair various library materials.

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2. Repairing western-style books

We will take books bound in the western style, the kind of books which are most familiar today, as our next example. In Japan, western-style books started to be published since the Meiji Era (1868-1912). These books using western paper can be repaired by making use of the features of washi – one big reason is its durability owing to the long fibers of the ingredient kozo (, mulberry family). For adhesives, we use starch paste, which enables washi to be removed easily when necessary by moistening, even after the treatment. We adopt this method so that the material can be returned to its original state if a better method is discovered in the future.

<<Image 1: A book bound together using threads>>

There are many variations in western-style binding. Image 1 shows a book bound with threads. It consists of multiple layers of paper folded together, called quires (折丁, oricho in Japanese). This type of book is created by sewing the folded sides of the quires together using thread. In the image, the crease of the quire has torn apart, and therefore cannot be rebound.

<<Image 2: A strip of washi is pasted to mend and strengthen the quire>>

<<Image 3 and 4: Rebinding the book>>

By pasting a strip of washi (image 2), the torn area can be mended and strengthened at the same time. The book can now be rebound using needle and thread (images 3 and 4), and will return to its original state when the cover is put back.

<<Image 5: A photo booklet from the Taisho Era>>

Shown in image 5 is a booklet with photographs attached, published in the Taisho Era (1912-1926). The spine is torn, and the staples used for binding have become discolored. The paper around these staples has also been worn away.

<<Image 6: The deteriorated paper which covered the photos has been replaced with washi>>

The thin paper which covers the photos has also deteriorated and become discolored. To repair this material, we first removed the staples and detached the front cover, and replaced the thin paper with washi (image 6). Then we pasted a strip of washi on the binding margin, and made small holes to sew it together using threads made of hemp.

<<Image 7: The front cover has been mended using colored washi>>

We selected colored washi that best matched the color of the front cover, and mended the cover from front and back (image 7).

<<Image 8: The front cover and text block were attached by washi>>

The cover and text block were attached by pasting washi on the binding margin, and the repairing process was completed.

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3. Repairing newspaper

<<Image 9: Newspaper repaired using tengujoshi, one of the thinnest kinds of washi>>

Paper used for newspaper is fragile and prone to deterioration. When it is torn, we apply tengujoshi onto the surface of the damaged area, from both sides (image 9). As tengujoshi is one of the thinnest kinds of washi, it enables mending without hiding the information on the material.

<<Image 10: Foreign newspaper of which the missing part is mended with washi>>

For newspaper which is partially missing, we choose washi that closely matches the original paper in color and thickness, tear the washi slightly larger than the missing area, and paste it using starch paste.

<<Image 11: Two strips of washi. The strip above was moistened with water and hand-torn, while that below was cut using an edged tool. The feathered fibers are effective in mending materials>>

We usually tear washi with our fingers instead of cutting it using edged tools. The edge of washi will have some long fiber extensions when torn after moistening, as shown in the upper part of image 11. Compared to the cut edge (as is shown in the lower part of image 11), the feathered edge allows the washi to blend in and gives a firmer hold to the text paper due to the smaller gap and increased adhesive area given by the extended fibers. Tears and cuts in materials are repaired by taking advantage of this feature of washi. We sometimes mend a material by pasting narrow strips of torn washi on the back of the damaged part.

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4. Repairing maps

Maps in the form of sheets are unfolded when stored at the NDL. However, some maps were kept folded before being brought to the NDL. These maps often have tears along creases due to deterioration.

<<Image 12: Lining a deteriorated map with washi>>

We reinforce these deteriorated maps by lining them with a slightly larger sheet of washi as shown in image 12.

<<Image 13: The map is dried over a karibari board>>

Once the lining is over, the map is pasted on to a drying board (image 13). This board is called a karibari board (仮張り板, lit. temporary mounting board). This is a traditional tool indispensable in Japanese paper mounting.

A karibari board is made by pasting about ten layers of washi over a wooden frame (image 14) and applying persimmon juice (柿渋, kakishibu in Japanese) to the surface (image 15). It is light in weight and easy to handle despite its size, and the persimmon juice makes it firm and water-resistant.

<<Image 14: Making karibari boards>>

<<Image 15: Persimmon juice is applied on the surface of the layered washi>>

The deteriorated material, after being lined with washi, is moistened and stretched. Then the material is mounted over the karibari board by applying starch paste on the margin of the washi. The material will gradually dry and shrink. Since it is stuck on with paste, the material will stretch out and become flat like the head of a drum. After it is completely dried, we remove the material and cut off the extra margin of washi. The karibari board is a significant tool for flattening and drying large materials in a limited space.

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5. Conclusion

In a series of two articles, we have introduced examples of our conservation treatments of library materials using washi. We hope that our readers realize that this traditional and splendid washi is essential in preserving and repairing different kinds of materials. Washi is heavily used in various scenes not only in Japan but all over the world. We will continue our efforts for the preservation and conservation of library materials.

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Related articles from the National Diet Library Newsletter:

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