Tokyo National Research Institute for Cultural Properties Center for Conservation Science
Department of Art Research, Archives and Information Systems Japan Center for International Cooperation in Conservation
Department of Intangible Cultural Heritage

Workshop on Conservation Science for Conservators of Japanese Painting and Calligraphic Works

Lecture by Ms. Sano on the safe handling of organic solvents
Workshop by Mr. Kimishima on how to remove stains

 To conserve Japanese paintings, calligraphic works and other pictorial artifacts, we are now increasingly required to have some knowledge of conservation science. To meet these demands of conservators who wish to learn how to handle chemicals, particularly those that have recently become more popular in restoration sites, and how to apply them in conservation and restoration works, the Tokyo National Research Institute for Cultural Properties and the Association for Conservation of National Treasures (ACNT) jointly conducted a workshop with training program for conservators from August 8 to 9, 2017, which included lectures on basic knowledge and practical work sessions. The workshop aimed to provide hands-on knowledge that can be applied to actual conservation works. To achieve this purpose, we designed a curriculum that would help participants accurately understand the chemical property of organic solvents and enzymes as well as the proper handling of basic laboratory instruments and chemicals for more effective and safer restorations.
 A total of 11 people, one from each corporate member of ACNT, participated in the workshop. Dr. Sano, Director of the Center for Conservation Science; Dr. Sato, Head of the Biological Science Section; and I provided lectures on the safe handling of organic solvents; integrated pest management (IPM) for cultural properties at restoration studios; and removal methods of adhesives and stains, respectively. Based on these lectures, the participants practiced removing various types of stains on the sheets of paper that we prepared, by using suitable solvents and enzymes. The practical work session also covered other topics such as the use of cyclododecane as a temporary protective coating for water-sensitive colorants. Mr. Kimishima, ACNT’s Senior Conservator, taught in the work session and provided hands-on training to the participants.
 The program ended with a lively Q&A session and discussion. We will continue to hold such workshop in the future.

Completion of the restoration works for the mural paintings in the Kitora tumulus

Packing for transportation

 The Tokyo National Research Institute for Cultural Properties (Tobunken) has been conducting the project “Work on the investigation of the preservation measures for Kitora Tumulus, a special historic site” since 2004. As the mural paintings in the tumulus required conservation treatments, it was decided that they would be removed from the tumulus and currently conserved externally. Three types of conservation treatments were conducted: maintaining the mural paintings in the tumulus, removing the mural paintings from the tumulus stone, and reconstructing the mural painting fragments. The removal of the mural paintings had been conducted for over 6 years, and the paintings were separated into 1143 fragments. The paintings have been reconstructed in the restoration facility in Asuka-mura, Nara prefecture. The Tobunken team has developed conservation techniques and performed experimental checks for this project, and the Association for the Conservation of National Treasures, an association of conservators for Japanese paintings, has applied the developed techniques.
 On August 24th and 25th, 2016, three reconstructed mural paintings, the south wall with suzaku, west wall with byakko, and the ceiling with an astronomical chart were moved from the restoration facility to “Shijin no yakata”. This museum opened on September 24th, and the three mural paintings was exhibited for a month.

Presentations at the Institute of Conservation in the UK

A lecture underway
A post-conference workshop

 From April 8 to 10, 2015, a conference entitled “Adapt & Evolve: East Asian Materials and Techniques in Western Conservation” took place mainly at the Brunei Gallery at the University of London. The conference was organized by the Book and Paper Group of the Institute of Conservation (colloquially known as ICON) in the UK.
 The conference consisted of tours of relevant institutions in the City of London, group events (presentations and question-and-answer panels), and various workshops. MASUDA Katsuhiko (an emeritus researcher at the Institute, currently a professor at Showa Women’s University), HAYAKAWA Noriko (a senior researcher at the Institute), and KATO Masato (a head of the Resource and Systems Research Section at the Institute) reported on the results of projects such as international training in Conservation of Japanese Paper (JPC) and the Cooperative Program for the Conservation of Japanese Art Objects Overseas as well as studies of the materials used to restore cultural properties. In addition, post-conference workshops were conducted after the conference. HAYAKAWA Noriko and KUSONOKI Kyoko (an associate fellow of the Institute) explained the traditional adhesives used in the field of conservation in Japan, and showed how to make starch paste and they instructed attendees in its application.
 According to the conference organizer, the conference was attended by about 300 people from around the world. During the question-and-answer session, the conference chair asked the audience about the JPC, and the answer revealed that 30 or more individuals who had completed the training were in attendance. Individuals who had completed other workshops organized by the Institute were also in attendance. Thus, the Institute plays a major role in introducing East Asian materials and techniques to Western conservation. In addition, many of the attendees asked that the Institute continue to provide information about conservation.

Investigative research on application of restoration materials 

Test application at Itsukushima Shrine

 The Center for Conservation Science and Restoration Techniques conducts investigative research on restoration materials for cultural properties. Various types of restoration materials are needed in a diverse range of fields such as architecture, and fine and applied arts.
 At Itsukushima Shrine, the center is involved in continuing investigative research on restoration materials for the large “Torii.” Itsukushima Shrine is located on the sea, in a severe temperature and humidity environment, directly exposed to wind and rain, and the effects of salts must also be taken into consideration. For such reasons, there are stringent conditions on the selection of restoration materials. Working time is also limited due to factors such as rise and fall of the tide. In selecting restoration materials, two types of testing are done in parallel: accelerated deterioration testing under various conditions in the laboratory, and exposure testing at the actual site.
 Specifications of filling material were finalized through research studies up to the last fiscal year, and surface finishing materials are currently being studied. Based on the results achieved to date, test application of a selected material was carried out on October 22 and 23. Going forward, the center plans to make follow-up observations, and continue investigations to enable proper selection of materials.

Testing to select repair materials for Itsukushima Shrine

Exposed test pieces under an open platform (stage)

 The Center for Conservation Science and Restoration Techniques studied materials to restore the Otorii gate of Itsukushima Shrine. The study selected materials for use in a coastal setting with harsh conditions such as high temperature and high humidity, immersion in water, and the presence of salts. Forced degradation tests are currently being performed in the lab and an exposure test is being performed on-site. Exposure on-site began in June 2010, and the water content in test pieces is being measured and deterioration is also being observed, in every 2 months. These tests will continue in the future, and plans are to verify deterioration via a strength test in 2011. Forced degradation tests in the lab include a UV irradiation test and temperature cycle test, and plans are to conduct a salt spray test in 2011.

Completed Removal of the Kitora Tumulus Wall Paintings

Inside the stone chamber with all plaster walls removed

 The Center for Conservation Science and Restoration Techniques has been removing the wall paintings of Kitora Tumulus as part of a project called the Investigation on Conservation for special historic site Kitora Tumulus, commissioned by the Agency for Cultural Affairs. We had aimed to complete the removal in the next spring term following the intensive removal of the paintings in the spring and autumn of 2009. However, we removed all plaster from the stone chamber walls during this term earlier than the planned schedule (autumn 2010). This work was attributed to the proficiency of the engineers in removal, as well as to the development and improvement of the machines, tools and materials promoted by Tobunken. The work in the stone chamber was finished in a series of conservation projects of Kitora Tumulus Wall Paintings, starting with the removal of Seiryu (blue dragon) in 2004. We will begin treating and mounting the wall paintings in the conservation facility.

Survey on Deterioration Status of Itsukushima Shrine

The damage caused by bark beetles and shipworms

 The Center for Conservation Science and Restoration Techniques is also examining the extent of deterioration of wooden buildings in the project “Study on assessment of influence of ambient environment on cultural heritage and countermeasures.” Among the wooden buildings subject to a severe outdoor environment, particularly the Itsukushima Shrine in Miyajima-cho, Hatsukaichi City, Hiroshima faces stern conditions, such as harsh weather and the influence of seawater. It is affected by intense UV rays, wind, rain, seawater and waves, and was also heavily damaged by gribbles and shipworms under the sea. We are now studying how to prevent the wood from deteriorating in this situation, and how to restore the deteriorated wood and what restoration materials to use. Therefore, we are conducting physical tests such as a strength test, curing test and exposure test in various forms at the local site. In this way, we are investigating the optimum techniques to use. We hope that the results obtained by such examinations will be adopted for other wooden buildings.

Completing Continuous Removal of the Kitora Tumulus Pluster

Removing plaster on side wall
Removed plaster piece

 The Center for Conservation Science and Restoration Techniques has been removing the mural paintings of Kitora Tumulus as part of a project “Investigation on Conservation for special historic site Kitora Tumulus” entrusted by the Agency for Cultural Affairs.
 Following the first work of removing in May, we continued the work in two periods of three weeks each, from October 19 to November 6, and from November 16 to December 4. Although the work in autumn took longer than that in May, performing the removal over periods of three weeks each enabled efficient removal progress. All plaster on the ceiling was detached by this latest work, and we will be able to resume removal of the plaster on the side walls for the first time in two years. We will continue to inspect the in side of the tumuls periodically, while irradiating UV-C to control microorganisms, and conduct removal again next year.

Evaluation Seminar, 2007 of the International Course on the Conservation of Japanese Lacquer

Presentation by a participant
Studying folk materials associated with urushi and collecting of urushi sap

 Evaluation Seminar, 2007 of the International Course on the Conservation of Japanese Lacquer was held for a week from September 10. This international course on conservation is a joint project with ICCROM, whose headquarter is in Rome. Courses on urushi (Japanese lacquer) and Japanese paper are held in alternating years. Since this year was the fifth year of the course on urushi, the format was changed; instead of the regular course, past participants met to hold an evaluation seminar. On the first two days, 11 participants made presentations concerning how they are utilizing what they learned in the course in their current work while on the last 3 days, the participants went on a study tour to deepen understanding about urushi. Presentations by participants revealed cases in which the experience and knowledge obtained during the three-weeks’ course in the past are being put to use in the conservation of cultural properties made of urushi in various nations. This and the exchange of diverse information concerning urushi were extremely meaningful not only for the participants but also for us in conducting future courses.

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