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 Basic Science for Conservators

With participants
Lecture on basic chemistry using molecular models
Practical session for the selection of organic solvents

 The Center for Conservation Science continues scientific research on the conservation and restoration of cultural property. Since FY 2021, based on our research, we have held workshops on basic science for conservators who have diverse experiences in the restoration of cultural property and museum curation and archiving.

 In 2022, the workshop was held for three days from October 31st to November 2nd. We provided lectures and practical sessions on basic scientific knowledge essential for conservation and restoration, including basic chemistry, science of adhesion and adhesives, chemistry of paper, pest damage control, and usage and disposal of chemical agents. Researchers of the Tokyo National Research Institute for Cultural Properties delivered lectures based on their expertise.

 We received 45 applications across Japan for 15 seats. In 2022, we invited 19 applicants from across Japan with varied backgrounds to the workshop; by contrast, in 2021, considering the COVID-19 pandemic, we accepted only those applicants who either resided in or commuted to Tokyo. Workshop content was carefully aligned with requests from the previous year. Participants expressed their appreciation for this workshop through the questionnaires provided. We received specific requests for disseminating scientific information used in actual conservation and restoration cases. We intend to continue this workshop series to meet these expectations.

Investigation of Conservation Environment for Wooden Architecture in Rock Caves

Measuring the surface temperature of the rock
Measuring the moisture penetration status above the rock
Measuring the surface temperature of the honden

 The Center for Conservation Science conducts investigations for the conservation environment of wooden architecture built in rock caves.

 The Natadera Temple in Komatsu City, Ishikawa Prefecture is a temple of the fusion of the Indigenous Hakusan Faith (the faith for Mt. Hakusan), and Buddhism. Its wooden  honden (main shrine), which is an Important Cultural Property, was reconstructed in 1642 in a rock cave created via natural erosion. In recent years, aseismic reinforcing works have been installed. Since then, moisture condensation has often occurred during spring to summer time, which is problematic because it causes wood decay. Therefore, it is desirable to reduce the frequency of moisture condensation to conserve the shrine and its decoration in good condition.

 To tackle this, the Center is conducting an environmental investigation to identify the occurrence factors of moisture condensation and to determine the appropriate countermeasures to reduce them. Rainwater, outer air, and heat capacity (ability to store heat) of the rocks affect the environment inside the cave. Therefore, the temperature and humidity in the cave, moisture penetration into the rocks, and surface temperature of the rock and the honden are being measured. We plan to pursue our investigation by continuous measurements of environmental data and analysis.

 Moisture condensation causes many problems at many masonry constructions and stone chambers of burial mounds. In recent years in particular, the rise of temperature and absolute humidity in the summer season increases the condensation occurrence risk. There is an urgent need to tackle the global environmental challenges. However, for now, we suggest the achievable countermeasures in everyday management.

Workshop – Nanocellulose Films in Art Conservation

Participants at the opening ceremony
Practical work

 In recent years, the investigations of conservation and restoration for cultural properties have expanded their targets not only to traditional cultural properties but also to modern artifacts and documents made of various types of materials. The Restoration Materials Section of the Center for Conservation Science invites experts from overseas and conducts workshops to meet these needs. In 2022, we invited Mr. Remy Dreyfuss-Deseigne, an expert who conducts research and application of nanocellulose films for conservation and restoration, to conduct a three-day workshop beginning on October 5th, 2022. Nanocellulose films are a kind of cellulose made from natural materials, which are transparent and stable. Therefore, nanocellulose films can be applied to transparent materials such as tracing paper and photo film with which traditional conservation materials do not work well.
 We received applications more than double the official capacity of 15 seats for this workshop from conservators. This indicated high expectations for the workshop. We accepted all applicants to the lectures for the morning sessions, but we needed to limit participants for the practical sessions in the afternoon. The workshop began with an inauguration ceremony, with opening remarks by SAITO Takamasa, Director General of TOBUNKEN, and then the lecturer, Mr. Dreyfuss-Deseigne was introduced. During the workshop, the lectures were held in the mornings and practical sessions in the afternoons. On the last day, a tour of TOBUNKEN was conducted to see TOBUNKEN equipment related to the workshop.
 This workshop with a lecturer invited from overseas was held for the first time in 3 years since the last one. The “face-to-face workshop” encouraged participants to raise very active questions and discussions. Participants said that they could build mutual collaboration among the workshop members. We recognized again the significant impact of in-person workshop, which could not be achieved online. We believe that our workshop helped in the actual reconstruction of cultural properties and conservation of archives.

Air Quality Investigation in the Museum Display Cases

Injecting nitrogen into the bag set in the display case
Extracting the air from the bag using a pump

 The Center for Conservation Science investigates the conservation environments of museums. Recently, the Kanagawa Prefectural Museum of Cultural History requested us to investigate the air quality in their exhibition cases. They detected some organic acids, however, the emission source was not identified. The emission source was needed for taking appropriate counter-measures. Moreover, the ratio of acetic acid and formic acid is called for as the current measurement was taking them collectively as organic acids.

 Therefore, the Preventive Conservation and the Analytical Science Sections decided to investigate the emission source by applying the air quality investigation methods developed by the Analytical Science Section. Five points including the floors of two wall display cases (big and small size), the display surface of a tabletop case, the display stand, and the back panel, were targeted. As shown in the photos, the targeted measurement points were covered with bags made of airtight film and the 4.5 kg lead rings were set to seal them. Then, after replacing the air inside the bags with nitrogen and leaving them for 24 hours, the air was extracted from the bags using a pump, dissolved in ultrapure water, and analyzed using ion chromatography. Consequently, we measured the amount of acetic acid and formic acid emissions. Simultaneously, we checked the sealing degree by the measurement of CO2 density change inside bags over time.

 We have identified the density of acetic acid and formic acid at each measurement point and will leverage these outcomes for future air quality improvement.

Investigation of Coloring Pigments Used in Kangetsu-do Hall of the Kotoku-in Temple

Investigation at Kangetsu-do Hall of the Kotoku-in Temple

 The Kotoku-in Temple, famous for its Great Buddha, has a hall called Kangestu-do Hall, transferred from Gyeongbokgung, a Korean royal palace. Kangetsu-do Hall faces various issues for its conservation and utilization, such as aging roofing tiles and outer walls as well as damage by wild animals. Dancheong were the original coloring pigments used in Kangetsu-do Hall at the time of its construction. This is very valuable because they exist in their original state. Their elements have not yet been elucidated; therefore, it is important to understand their status. Through these examinations and discussions, we decided to collect basic information related to the coloring pigments used in Kangetsu-do Hall.

 Responding to the request by the Kotoku-in Temple (chief priest: Prof. SATO Takao), INUZUKA Masahide, HAYAKAWA Noriko, HAGA Ayae, and CHI Chih lien of the Center for Conservation Science of Tokyo National Research Institute for Cultural Properties (TOBUNKEN) conducted on-site investigation of coloring pigments on the building components of Kangetsu-do Hall using portable analytic equipment on July 6th and 7th, 2022.

 As this investigation’s first step, reflectance spectrometry was conducted using a hyperspectral camera to investigate two-dimensional color information, focusing on the places where the original paintings from the construction time were presumed to remain. We then selected some places that were academically interesting based on the reflectance spectrometry data and performed further detailed analysis using X-ray fluorescence analysis. We plan to analyze in detail the data obtained by these two types of analysis methodologies, further investigate the unique coloring pigments used in the Joseon Dynasty, and use this information for future conservation and utilization.

MoU for Research on Conservation and Restoration of Cultural Properties in Minamikyushu City Concluded

SAITO Takamasa, Director General of TOBUNKEN and Mr. NURUKI Hiroyuki, Mayor of Minamikyushu City holding the signed MoU
Meteorological observing station now installed close to the water tower of the former Chiran Airfield site (cultural heritage designated by the city) – right hand side in the fence

 The Tokyo National Research Institute for Cultural Properties (TOBUNKEN) and Minamikyushu City of Kagoshima Prefecture have jointly conducted research on conservation and restoration of individual cultural properties located in the city from around 2008. Now, we decided to conclude “MoU for Research on Conservation and Restoration of Cultural Properties Designated by Minamikyushu City” and explore further collaboration as joint research. Taking this opportunity, we conducted the conclusion ceremony of this MoU in the city office of Minamikyushu City on July 20th, 2022. At the ceremony, the project details were explained and SAITO Takamasa, Director General of TOBUNKEN and Mr. NURUKI Hiroyuki, mayor of Minamikyushu City signed them, after the explaining the project overview.

 Minamikyushu City has total 191 designated cultural properties. Among them, modern cultural heritage, including the buildings at the former Chiran Airfield site of the Imperial Japanese Army, as nation registered cultural properties and The Army Type-4 Fighter Aircraft, “Hayate”, a cultural property designated by the city are well known as mandatory materials in Japanese modern history. However, the modern cultural heritage’s characteristics differ from those of traditional cultural properties in volume, materials, functions, and others. Therefore, it often requires new methodologies for conservation and restoration.

 This joint research aims to solve technical issues related to conservation and utilization of these cultural properties, develop new conservation methodologies, vitalize research activities, and contribute toward promotion of public awareness of local cultural properties by collaboration of TOBUNKEN and Minamikyushu City. We will also provide information beneficial to other local governments who have the same or similar challenges by disseminating the research outcomes.

2022 Training for Museum Curators in charge of Conservation (Advanced Course)

Visiting the Analytical Science Section
Lecture on conservation of Modern Cultural Heritage

 The Tokyo National Research Institute for Cultural Properties (TOBUNKEN) held the “2022 Training for Museum Curators in Charge of Conservation (Advanced Course)” for five days, from July 4 to July 8, 2022.

 This training is an application version of the trainings for museum curators in charge of conservation, which were held from 1984 to 2020 for curators in charge of material conservation to master basic knowledge and techniques necessary for environmental management, evaluation, and improvement.

 From 2021, we reorganized the training into two courses: 1) basic course, focusing on conservation of environment by the National Center for the Promotion of Cultural Properties, and 2) advanced course, focusing on curators who attended the course before and/or who have similar experiences, by TOBUNKEN.

 We provided lectures and workshops mainly based on research outcomes of each research area of the Center for Conservation Science, along with lectures from external lecturers related to various conservation and restoration in the advanced course. We are pleased to have organized face-to-face training with 18 participants, with thorough prevention measures for COVID-19 pandemic. We believe that the participants made their networks there.

 Based on questionnaires after the training, we understand that the participants were well satisfied. We could know their voices: “I will try various techniques from this training in our museum,” “I could review my understandings and obtain new knowledges. It was very beneficial for me,” and “It was a very useful week for me.” Henceforth, we will work to provide more useful training to curators in charge of conservation.

Video Documentation of the Manufacture of Carving Tools for Sculpture – Recording Survey of Tools and Raw Materials used for the Preservation and Restoration of Art and Craft Objects

Video and photo documentation of the chisel manufacturing process
Manufacturing chisels for sculpture

 Understanding the manufacturing situation of tools and raw materials used for restoration is extremely important to continue sustainably restoring cultural properties. However, “the Research Project on Preservation and Restoration of Tools and Raw Materials,” commissioned to the Tokyo National Research Institute for Cultural Properties (TOBUNKEN) by the Agency for Cultural Affairs since FY2018 revealed that the manufacture of tools and raw materials for cultural property restoration faces many challenges rooted in the following two factors. The first is the human factors of aging manufacturers and a shortage of successors, and the second is factors caused by shifts in social structures, such as deteriorating business and the unavailability of raw materials. Considering this research outcome, the Center for Conservation Science initiated a project to collect fundamental physical property data and to document tools and raw materials necessary to preserve and restore cultural properties. The Center has worked on this project with the Department of Art Research, Archives and Information Systems and the Department of Intangible Cultural Heritage. This monthly report presents the documentation survey of chisels for sculpture, the manufacture of which will cease.

 Chisels and saws are key tools to restore wood carving cultural properties because new timber materials may be carved and used as repair materials. Konobu Ltd. (Konobu), founded in the early Shōwa era (early 20th century) by the Takiguchi family, specialized as carving tool smiths. Since then, this smith has manufactured chisels for sculpture; Mr. SAITO Kazuyoshi succeeded their manufacturing techniques. Their products have been favored by many in charge of wood carving restoration and wood carving itself. However, Konobu stopped accepting new orders in October 2021 and expressed that they would soon close their business. TOBUNKEN used videos and photographs to document their full manufacturing process of chisels for sculpture, as well as their equipment and smith tools in interviews from May 23rd to 27th, 2022. Mr. KADOWAKI Yutaka of BIJYUTSUIN Laboratory for Conservation of National Treasures of Japan and the Agency for Cultural Affairs cooperated in this documentation survey.

 Unfortunately, it became almost impossible to experience and observe in person the Konobu chisel manufacturing process. We plan to organize the survey records to serve as a clue for future generations who want to reproduce chisels for sculpture.

Research Presentation at the Symposium in New York – Conservation Thinking in Japan

Presentation by HAYAKAWA Noriko

 HAYAKAWA Noriko of the Center for Conservation Science spoke about the relationship between techniques and materials for cultural property restoration in Japan titled The Relationship Between Traditional Painting Materials and Techniques in Japan from a Scientific Perspective in a talk at the symposium held in Bard Hall, New York City, United States, on May 6th and 7th 2022.
 This symposium titled Conservation Thinking in Japan and India was held both in person and online by Bard Graduate Center with support from the Andrew W. Mellon Foundation. There, experts on restoration of Japanese cultural properties and fine art history introduced their latest research from Japan and other countries.

 HAYAKAWA introduced two primary points among research in the Restoration Materials Section: the fact that furunori (aged paste) used for restoration of paintings is corelated to fringe materials and techniques, and an assumption that changes in the manufacturing process for silk, a support material of paintings, altered its string forms and preservability, which then impacted painting expression.

 Tours around related facilities and other meetings were held before and after the symposium, where useful discussions were conducted based on actual restoration cases.

 Scientific elucidation of materials and techniques is required even during everyday operations in restoration and material production. Opinion exchanges with other experts triggered further research. This presentation was a precious opportunity to disseminate our research outcomes to a wider audience.

The Third Seminar on the Survey and Management of Conservation Environment: Chemical Substance Absorbent for Air Cleaning

Seminar in the meeting room

 A series of seminar on the survey and management of conservation environment is organized annually, targeting the curators in charge of conservation for materials in museums and researchers engaged in conservation of cultural properties. These seminars aim to share common understanding on the surveys, assessment methods and improvement of conservation environment, and materials and tools for safe storage. The first and second seminars were organized by the National Center for the Promotion of Cultural Properties (CPCP) and the third was held with a co-sponsorship of CPCP and the Tokyo National Research Institute for Cultural Properties (TOBUNKEN.)

 In the first seminar, titled the Survey and Assessment of Air Environment Using Kitagawa Detection Tubes, usage and appropriate assessment methods of Kitagawa detection tubes, which were widely used for quantitative analysis of chemicals in the air in the exhibition and storage rooms, were explained. In the second seminar, titled Neutral Papers as Materials Used for Document Conservation, the scientific character of paper, characteristics and standards of neutral paper, and appropriate usages of conservation containers made of neutral paper were explained with hands-on practice. Neutral paper is widely used as a material to create document conservation containers in storage and stack rooms.

 The theme of the third seminar was chemical substance absorbent. Recently, concerns about chemical substance emission from the building and interior materials and its impact on the documents, as well as methods to improve the situation have attracted people’s attention. However, we are still exploring the best possible ways to clean the air in exhibition and storage rooms. Therefore, we invite a company that develops chemical substance absorbent to explain methods of selecting appropriate chemical substance absorbent, as well as the adsorption phenomena, principle and structure of absorbent, and environmental factors related to adsorption efficiency.

 We conducted this seminar with eight participants in person and distributed it online for the prevention of the spread of COVID-19 infection. A total of 30 people participated in the seminar. Participants provided their opinions on the usefulness of the seminar because they could learn from the principle to the practice, stating, “I could well understand the types and mechanisms of gas adsorption,” and “as I understood the principle of gas adsorption and measurement methods, it would get easier to assume the solutions.”

 We plan to continue the seminars by setting themes that are necessary for daily practices, from the viewpoint of conservation science.

Analytical Survey Using Hyperspectral Camera at the Baijōsan Kōmyōji Temple

Preparation for the survey
Discussion about the investigation parts

 Department of Art Research, Archives and Information Systems has been engaged in a series of surveys on Rakan-zu (a painting of Arhat, an enlightened Buddhist high priest) painted in the Yuan Dynasty, owned by the Baijōsan Kōmyōji Temple in Minato Ward, Tokyo. Please refer to our online monthly report for this survey. (

 Near-infrared imaging and fluorescence imaging produced by optical survey suggested that the new artificial iwa-enogu (mineral pigment used in paintings) could have been used to add colors on several parts of this painting.

 It is expected that, in addition to the observation on the imaging data including high-definition imaging, scientific analysis survey can provide additional data from the different approaches. Then, we, INUZUKA Masahide, CHI Chih lien, TAKAHASHI Yoshihisa from the Center for Conservation Science, and EMURA Tomoko, YASUNAGA Takuyo and MAIZAWA Rei from the Department of Art Research, Archives and Information System conducted a survey on Rakan-zu by reflectance spectrometry at the Baijōsan Kōmyōji Temple on January 19th, 2022.

 Reflectance spectrometry can identify the kinds of coloring materials used in the work by reflectance spectrometry formation, how the reflectance of the surface against wavelength of light. Furthermore, hyperspectral camera, which we used this survey, shows the distribution of the same reflectance spectra in two dimensions simultaneously.

 We plan to identify the materials and places for adding color by analyzing the data which we have gathered in this survey.

Molecular Biological Analysis for Identifying Cultural PropertyPests Using Their Frass

Method to identify cultural property pests using DNA as an identifier
Collecting frass from buildings

 Damages caused by cultural property pests are a serious and global threat to cultural property conservation because they result in significant losses of cultural property materials and largely reduce their values. Thus, it is critical to identify and take appropriate measures as soon as the cultural properties start showing signs of damage to prevent further loss. However, we may encounter a situation in which it is difficult to identify “criminal” species even by experts, as we cannot find living insect pests but only their frass. To overcome these difficulties, the Biological Science Section has identified cultural property pests using DNA extracted from frass as an identifier.

 As the outcomes in FY2021, we succeeded in establishing a method to identify species by frass for the major pests boring bamboo, which are used as part of cultural property buildings and to create craft works. The method includes collecting bamboo-boring pests, extracting the DNAs, and determining a short section of sequence from a specific gene. The datum is registered in the international databases, combining the morphological characteristics and the DNA sequence. Then, DNA is extracted from frass collected at rearing containers and outside buildings, determining their target sequence. The resulting sequences are compared to the reference databases to find the matching species. Before the establishment of the method, it was difficult to determine the base sequence, because the DNA extracted from the frass was either too small or contaminated by DNA of other species. However, specific primers for PCR constructed in this study enabled us to succeed in identifying “criminal” species using anonymous frass collected in the cultural property buildings, rather than being limited to laboratories. Please refer to “Science for Conservation” #61 for further details.

 In the future, we plan to further develop specific primers to identify species by frass of cultural property pests in various phyletic lines, and enable easy usage in the field by upgrading the base detection system, including standardization and simplification of methods. We will continue to proceed with the study to achieve these objectives.

Basic Research for Preservation and Restoration of Usuki Stone Buddhas, a National Treasure

Adherence sample setting for exposure test
Water content meter setting to measure the amount of water in the rock

 Usuki Stone Buddhas, a National Treasure, are a group of “magaibutsu” (Buddha statues directly carved into rock face) sculpted niches that were carved on ignimbrites between the late Heian period and the Kamakura period. They consist of the following four clusters: the Hoki First Cluster, the Hoki Second Cluster, the Sannosan Cluster, and the Furuzono Cluster.

 Weathering has partially progressed in these Buddha statues. Although protected by the niches from rainfall and winds, their surfaces have been impacted by repeated frosting and melting of underwater and rainwater during winters, and by flaking and granulating as a result of salt deposition due to evaporation in dry season. Therefore, weathering prevention methods such as building protective shelters, controlling river-bed water running behind the statues, and remounting falling pieces were adopted in the past. Tokyo National Research Institute for Cultural Properties (TOBUNKEN) has been engaged in these efforts for a long time.

 A new joint research with Usuki City has now started to preserve and restore the Stone Buddha Statues. The surfaces around one knee of the seated Amitabha Tathagata Buddha statue in the Hoki Second Cluster have rebegun flaking and falling despite early preservation and restoration efforts. Via environmental research, we plan to monitor the change in temperature and humidity in the newly built protective shelters and review the water content in the rock, in addition to studying materials and implementing methods to strengthen and remount falling pieces. In preparation, we set the measuring equipment and adhesive samples for outdoor exposure testing on October 18th and 19th.

 We plan to regularly review the measured data and observe the efficacy of adhesive samples against the weather, while continuing to discuss appropriate actions for the preservation and restoration of the Usuki Stone Buddha Statues with the Agency of Cultural Affairs, Oita Prefecture, and Usuki City.

A Workshop on Basic Science for Conservators

Lecture on how to handle lab instruments

 The Center for Conservation Science conducts scientific research on the conservation and restoration of cultural property. In 2021, we introduced a workshop on basic science, based on our research, for conservators who have diverse experience in restoration of cultural properties and museum curation and archiving.
 The workshop was held for three days from September 29th through October 1st, 2021. We provided lectures and practical sessions on basic scientific knowledge that is important for conservation and restoration. It included basic chemistry, science of adhesion and adhesives, chemistry of paper, and pest damage control. The researchers of Tokyo National Research Institute for Cultural Properties delivered the lectures, based on their areas of expertise.
 We received 44 applications from across Japan for 15 seats. Fifteen applicants, who either resided in or commuted to Tokyo, and had the desirable expertise, participated in the workshop keeping in mind the on-going COVID-19 pandemic.
 The participants expressed their appreciation for this workshop through the questionnaires that were provided. We received requests for further scientific information on more advanced conservation and restoration cases. We intend to continue this workshop series to meet these expectations.

Investigations of Kitora Tumulus Wall Paintings Covered with Mud

Investigation using X-ray fluorescent analyses

 The Protection of Tumuli and Wall Paintings Project Team consisting mainly of researchers from Tokyo National Research Institute for Cultural Properties(TOBUNKEN)and the Nara National Research Institute for Cultural Properties has been working on research studies to preserve and restore the wall paintings of Takamatsuzuka Tumulus and Kitora Tumulus. Compared with the wall paintings of Takamatsuzuka Tumulus, the wall paintings of Kitora Tumulus are characterized by the twelve signs of the zodiac, depicted as animal heads on human bodies, three of which are featured on each wall along with the Four Divine Creatures and Star Atlas and others.
 While six figures out of twelve—the Rat, Ox, Tiger, Horse, Dog, and Boar—have been identified, the Rabbit, Sheep, and Rooster are completely lost since the plaster where the paintings should be is missing. The rest, that is, the Dragon, Snake, and Monkey, are not yet identified because the surface of the walls is covered with mud. These three pieces of walls that could contain those paintings are currently not reassembled, but are preserved in the facility for conservation and restoration of Takamatsuzuka Tumulus wall paintings.
 The material investigation group and restoration group of this project team worked together on an investigation using X-ray radiography in 2018 and found some radiographic images that seemed to show something drawn in the space where the Dragon was expected to be, but many questions remained. Then, in December 2020, X-ray fluorescent analyses were performed on the parts of the walls where the wall paintings of the Dragon and Monkey could possibly exist. Some mercury was detected, indicating that the figures might be present.
 Following this outcome, on August 11th, 2021, further X-ray fluorescent analyses were conducted on the part of the wall where the Snake artwork was suspected to be. Three members of the Center for Conservation Science, TOBUNKEN—INUZUKA Masahide, HAYAKAWA Noriko, and CHI Chih lien—participated in this investigation. X-ray fluorescent analyses were conducted at spots distanced 2 cm apart where the Snake painting was expected to be. The detection of mercury indicated that the painting was indeed present.
 These results were reported in the “29th Committee on Preservation and Utilization of Tumulus Wall Paintings” held on August 31st, 2021 by the Agency for Cultural Affairs.

X-ray image of the piece of the wall where the Snake painting could be present (left) and distribution of mercury signal strength (right)

2021 Training for Museum Curators in Charge of Conservation (advanced course)

Lecture on the Types and Characteristics of Restoration Materials
A Visit in Pest Control Practical Training

 During a five-day period of July 5–9, 2021, we held the 2021 Training for Museum Curators in Charge of Conservation (advanced course). Last year, we held this training jointly with the National Center for the Promotion of Cultural Properties. In order to clarify the content of the training and to make it more beneficial for museum curators in charge of conservation, this fiscal year, we decided to divide the training into the “Basic Course,” implemented by the National Center for the Promotion of Cultural Properties, and the “Advanced Course,” implemented by the Tokyo National Research Institute for Cultural Properties.
 The Tokyo Metropolitan Government has been implementing intensive measures to prevent the spread of COVID-19, and we thoroughly conducted temperature inspections, sanitization, and mask-wearing policies during the training.
Each laboratory of the Center for Conservation Science led the training on a one- or half-day basis, providing lectures and practical training in accordance with their respective specialties. Since advance-level courses are offered to people who have already received training for curators in charge of the conservation of museums, most of the attendees had an awareness of the issues and challenges faced by their own museums. On the last day, a lecture on disaster prevention and the mitigation of damage to cultural properties was given in light of recent natural disasters. This was a valuable opportunity to consider how to deal with and implement measures against natural disasters in museums, as well as the roles of the institutions in disaster prevention with regard to cultural properties.
 In questionnaires, many participants stated that the training was helpful, such as by increasing the knowledge and skills that would be helpful in carrying out their work in the future.
 This was the first time the training was held as an advanced course, but since the issues of the training have been clarified, we would like to improve it next year and in the future.

An Examination of Armor Using X-ray Radiography and X-ray Fluorescence Analysis

Survey of Armor by X-ray Fluorescence Analysis

 At the request of the Kariya city Museum of History, INUZUKA Masahide of the Center for Conservation Science, conducted an analytical survey of a suit of armor. As part of these materials, the helmet became a designated cultural property of Kariya City in 1984. The location of items other than the helmet, such as the torso of the armor, only came to light a few years ago. The degree of damage to these other parts of the suit armor is much more severe than to the helmet, but they were additionally designated as cultural heritage by Kariya city in 2019 and deposited at the Museum.
 A project to preserve and restore these materials will be implemented in the future. To collect basic data for this purpose, a structural survey using X-ray radiography and a pigment analysis using X-ray fluorescence analysis were conducted at Tokyo National Research Institute for Cultural Properties on May 31, 2021.
 Images taken with X-ray radiography provided information on the structure of the helmet and torso, the number of components that comprise the armor, the position and number of studs, and other information. We also conducted an X-ray fluorescence analysis of the pale orange-colored portion on the surface of the helmet, leveraging a device that specializes in analyzing cultural properties, which are large in size and have a three-dimensional structure, with high sensitivity, as shown in the photograph. The results of these surveys will be used as reference materials for future restoration work.

A Seminar Organized on “Exhibition Environments for Conservation and Utilization” Relationships between Lighting, Colors, and How One Looks

A scene of the seminar

 As part of a research project titled “Exhibition Environments for Conservation and Utilization” by the Center for Conservation Science, a seminar on “Exhibition Environments for Conservation and Utilization” – Relationships between Lighting, Colors, and How One Looks was organized to sum up research on lighting on March 4th, 2021. Reports on cases that put emphasis on ideal lighting for exhibitions at art and other museums while taking into account conservation of cultural properties had been predominant up until then. This time around, however, we asked experts in the area of lighting, which had not been taken up very much in the area of cultural properties, to share their insights into lighting with us from a perspective that was a little different from conservation.
 First of all, Ms. SANO Chie, an honorary researcher at Tokyo National Research Institute for Cultural Properties (TBUNKEN), who had taken the initiative in this project, gave a lecture on the flow of research into lighting at the Center for Conservation Science as an introduction. This was followed by lectures that covered a broad range of subjects delivered respectively by Prof. MIZOKAMI Yoko (Graduate School of Engineering, Chiba University), who specializes in vision science, vision engineering, visual information processing, and color dynamics, Prof. YOSHIZAWA Nozomu (Department of Architecture, Faculty of Science and Technology, Tokyo University of Science), who studies evaluation techniques for architectural light environments, and Prof. YAMAUCHI Yasuki (Graduate School of Science and Engineering, Yamagata University), who carries out research on visual information processing, color dynamics, illuminating engineering, and image processing.
 As a state of emergency was issued due to the COVID-19 pandemic, the seating capacity was limited to up to 30 in the seminar room, whose seating capacity is normally 120, but a face-to-face seminar proved extremely productive. Participants commented that the lectures delivered on a face-to-face basis were meaningful and that they were able to deepen their understanding of lighting, indicating that the seminar had a high satisfaction level. Meanwhile, we announced this seminar by limiting the recipients to art and other museums etc. in and around the Kanto region to prevent the spread of COVID-19. Thus, we decided to record the seminar and publish it on TOBUNKEN’s YouTube channel for a limited period of time. Let us encourage those who were unable to participate in the seminar in person to view it on this occasion.
You can view it from May 10th through July 30th, 2021 at:

The 2nd Meeting of Tumulus Mural Preservation Project Team in FY2020 Held Online

 On February 16th, 2021, Tokyo National Research Institute for Cultural Properties and the Nara National Research Institute for Cultural Properties held a meeting of the Tumulus Mural Preservation Project Team. The Tumulus Mural Preservation Project is aimed at the permanent preservation of Takamatsuzuka Tumulus Mural and Kitora Tumulus Mural, both of which are national treasures. The two Institutes have been taking the lead in promoting the project for many years. Currently four teams, namely the conservation and utilization team, the restoration team, the material research team, and the biological environment team are conducting research, respectively. Tokyo National Research Institute for Cultural Properties, the Nara National Research Institute for Cultural Properties, and the Agency for Cultural Affairs held the 2nd meeting online as the state of emergency had been declared to prevent the spread of the novel coronavirus.
 At the meeting, one team explained the creation of a 3D reconstruction model of the excavation and research areas of the tumuli. Other teams reported on the condition of the murals and non-contact optical analysis of the murals. The last team discussed the results of monitoring for microorganisms and the temperature and humidity at the preservation and management facility for Kitora Tumulus Mural as well as at the temporary repair facility for Takamatsuzuka Tumulus Mural. Careful discussion took place based on these reports. The reports consolidated at the meeting were made public at the 28th meeting of the Review Committee on the Preservation and Utilization of Tumulus Mural on March 23rd, 2021. Committee members gave suggestions and advice regarding the direction of future research and activities.
 The handouts and minutes of the meeting are posted on the Agency for Cultural Affairs website. If you are interested, please see the link below.

 The repair of Takamatsuzuka Tumulus Mural was completed by the end of FY2019. The installation of a new facility that is suitable for public viewing has been under discussion. There are many issues to consider such as the load on the mural and changes in the environment associated with the transfer from the temporary repair facility to a new exhibition facility. Nevertheless, the project team will verify feasibility, taking into account the research on the permanent preservation of both murals conducted so far.

A seminar on the analysis of materials, structures, and conditions of cultural properties: Lead corrosion affecting cultural properties and the air

The seminar is underway

 In the research project “Research on the Analysis of Materials, Structures and Conditions of Cultural Properties”, the Center for Conservation Science focuses on the physical and chemical characteristics of cultural properties based on the investigations of their materials and structures using various analytical methods. In particular, the Analytical Science Section has been studying the problem of the corrosion of lead composing cultural properties.
 In order to summarize the research, a seminar on the “Corrosion of lead composing cultural properties and air environment” was held on December 14th, 2020. Invited were experts in art history (HASEGAWA Shoko of Seikado Bunko Art Museum and ITO Tetsuo of Agency for Cultural Affairs), conservation science (KOTAJIMA Tomoko of National Ainu Museum), and restoration (MUROSE Tasuku of Mejiro Institute of Urushi Conservation) were invited. At the seminar, lectures were presented on examples of art works consisting of lead, the current situation and problems concerning lead corrosion in art works, and basic knowledge of lead corrosion from a scientific point of view. In addition, the latest information about the relationship between lead corrosion and air environment and examples of restoration were shared and discussed. (Attendance: 20 individuals).

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