Staff working in the repair room
Making of storage boxes
Kanba : This is another repair room. One of the tasks to be performed here is to make a variety of storage boxes like these. There are many types of boxes. We have made appropriate boxes and mats in accordance with a variety of documents, Japanese books and Ukiyo-e, which are stored in this museum. Ms. Yonekura is in charge of the tasks.
Yonekura : These are special storage boxes for Japanese books. Pieces of "Inpu," a collection of seal impressions gathered into book form, of various sizes have been stacked in storage boxes. In order to prevent a bottommost book from being damaged by the pressure of weight of upper boxes, these boxes were created. These projecting parts inside a box absorb the weight of upper books. Since the weight does not directly put pressure on lower books, books can be stored in a natural state. A flap is attached to a box in order to prevent dust and insects from entering the box. Depending on book conditions, we also make a box with cushions inside it. The inside of this cushion is cotton, which is wrapped by wrinkled Japanese paper. The cushion protects damaged edges of a book, so the book can be safely stored as it is.
The reason why we have made these large boxes for small books is that we have made the boxes in accordance with a specific standard in order to put the books in order. Although sizes of the books vary, all the books are stored in boxes of the same standard. There are three standards for boxes so that we can systematically classify books. Previously used boxes were very heavy, and pressure was directly put on books because the books were contained in boxes without any cushioning material. Originally, Japanese books were stored in a stacked manner. However, that manner has a disadvantage that weight is directly put on the books. Compared to the old boxes, the present boxes are much lighter, and weigh about half as much.
The basic idea of these boxes comes from the special archival boxes used in the Library of Congress in the United States. These boxes are the same type of the special boxes. Books are stored upright in the United States, so the boxes are shaped like this. In Japan, books are stored in a stacked manner, so these boxes were originally designed to allow the thickness of upper books. (continued in the lower column)
Kanba : Next, I will explain about Ukiyo-e. These pieces of Ukiyo-e were made in the Edo Period. These had been framed with a tarnished mat and exhibited as they had been. The paper itself is highly acidic, so it is discolored like this. Since pieces of Ukiyo-e have been stored with such discolored brown mats, there was a possibility that the Japanese paper, dyes and pigments might be significantly affected by them. Therefore, we have been replacing those old mats with new neutral paper mats. There are about 10,000 pieces of Ukiyo-e in this museum. We are replacing old ones with new ones everyday. If approximately 500 pieces is replaced in a year, it will take about 20 years to complete the task. (continued in the lower column)
Discolored acidic paper mat
Newly prepared neutral paper mat
A piece of Ukiyo-e with a new mat
This piece is properly framed with a mat. Ukiyo-e will be exhibited in this form. A sandwich-shaped mat is placed under a top window mat. If there is no sandwich-shaped mat under a window mat, the window mat directly presses the paper. Actually, when Ukiyo-e is stored, 10 pieces of it are stacked. The bottom piece receives the weight of nine pieces of Ukiyo-e. If the paper is pressed with strong pressure, there is a possibility of making a depressed line at edges of the paper. In order to avoid it, another mat is inserted between a window mat and the paper. Therefore, the top window mat does not come into contact with the paper directly. Since each piece is carefully finished, it takes a lot of time. Sizes of window mats vary. Mats should be made to suit each piece of Ukiyo-e so that the edges of the mat slightly overlap the paper. Mats are cut by a tool called "mat cutter" that is controlled by computer. We use that tool to cut out window mats. (continued in the upper right column)
Q : Japanese old materials were made with the shaku-kan system of measurement. What scale is used for these materials?
Kanba : Basically, the metric system of measure-ment is used. Measurements of "shaku," "sun" and "rin" are used for the formerly mentioned thorough restoration which uses the traditional technique "Soko." Also, all tools were made using that measurement system.
Q : Could you explain about the three standards you mentioned before? Are books stored in a stacked manner on shelves?
Yonekura : These are a variety of Japanese books called "Inpu," a collection of seal impressions. There are many different sizes of Inpu. These books are broadly categorized into three groups. We have made storage boxes slightly larger than the largest books. This set of boxes is used for the Inpu collections, and another set is used for other collections. So, this standard is not applied for all materials in this museum.
Kanba : Shelves, on which books are stacked, are set at intervals of about 30 centimeters. The difference between Japan and the United States, which I mentioned before, is also found in the customs relating to storage. It is not necessarily appropriate to say which way is better, but, as Ms. Yonekura mentioned before, we devised means of protecting books from pressure by attaching projecting parts inside a box.
Q: Can I see that work process?
Kanba : This work was done by French restorer Valery Lee. These are a kind of album called "Gyofu." It is an illustrated book of fish, created in the late Edo Period. One of the illustrators who drew the pictures of fish is Yuichi Takahashi. It can be called the Tokyo National Museum version of an illustrated book which was created by cutting and pasting a variety of fish drawings. If a person, who does not know the structure of "Gyofu," flip through the pages, the paper of the book might get turned up. So, in order to ensure handling safety, these pockets are attached to necessary places. Also, it takes a lot of time to repair all wormholes, so we have applied "minimum treatment" in which minimum necessary repairs are conducted.
Q: Are these forms of books generally stored in this case?
Kanba : This case was designed by the staff of this museum in order to store books. Although this album was made in the Meiji Period, it is fairly dated and damaged. We are inclined to think that it is better to replace the old paper with new one when repairing it. However, this is the important album from the Meiji Period. The book form itself is meaningful, and the album has not deteriorated. It can be properly used if repairing it. Also, the repaired one is better because its historical value still exists in it. So, we are planning to store it while maintaining its present state. (continued in the lower column)
Pockets attached to each page of "Gyofu"
"Gyofu," a collection of a variety of fish drawings gathered into book form
Humidifier
Kanba : These are tanks of humidifiers. A season of using humidifiers is over, so we are going to clean and store them. The air is dry and humidity is low during winter. As I mentioned before, 50 to 60% of relative humidity is appropriate for cultural properties. However, there are some places in this museum where it is difficult to maintain appropriate humidity. Regrettably, there is no way to cope with it because this building is very old. Humidifiers are individually installed at those places to increase humidity. In order to maintain appropriate humidity, we should continue to add water to humidifiers.
Therefore, the museum staff members, in turn, refill the humidifiers everyday during winter. On the other hand, humidity might reach over 60 % in summer, so we need to dehumidify. In that case, dehumidifiers are installed, and the staff members, in turn, remove the deposited water. All the curators and staff work together to do these tasks. It is our effort to maintain the museum.
Q : Do you use special water? Is a substantial amount of water used in the whole building? Is pure water procured in the museum?
Kanba : We have been using ion-exchange water. Tap water includes impurities, so we do not use it. There are 30 humidifiers in the museum, and each humidifier has two tanks. About five tanks per day, or ten tanks per day during peak season, should be prepared. The humidifiers are used for three months. Since the museum has an ion-exchange water production system, filtered tap water is used for the humidifiers.(continued in the next page)
Water tanks used for humidifiers
Staff working in the repair room