DAZAIFU, FUKUOKA PREF. – Setsuo Imazu of the Kyushu National Museum was greatly impressed and surprised when he viewed a nearly complete replica of a seated statue of Kukai in July because it so closely resembled the original, which is kept at Kongobuji, the head temple of Koyasan Shingon Buddhism, on Mount Koya in Wakayama Prefecture.
Kukai (774-835) was the Japanese monk who founded the Shingon, or “True Word,” school of Buddhism. He is also known as Kobo-Daishi, or the grand master who propagated the Buddhist teaching.
The 83.5-cm-tall statue is believed to have been made sometime between the 14th and 17th centuries. Kongobuji decided to produce a replica in time for the 1,200th anniversary in 2015 of the founding of Mount Koya as a monastic center by Kukai.
The Kyushu museum, in Dazaifu, Fukuoka Prefecture, is the only cultural asset conservation facility in Japan equipped with a 3-D measuring device, computerized tomography scanner and 3-D printer. It is Imazu’s job to manage the cutting-edge equipment, and he is providing his expertise to the replica project, which was farmed out to an Otsuka Ohmi Ceramics Co. factory in Koka, Shiga Prefecture.
A combination of the 3-D measuring instrument and CT scanner produces “perfect measurement data as every detail — even the shadows and structures inside an object — can be photographed,” Imazu said.
The machines make it possible to recognize structures, manufacturing methods and repairs of cultural assets without damaging them, he said.
“Because (complete) replicas can be produced based on the data collected, we can ensure the risk management of cultural assets even if they are lost in a disaster or stolen.”
Imazu, 59, was born in Wakayama and majored in archaeology at a university in Tokyo. He became interested in conservation science after becoming a frequent visitor to the National Research Institute for Cultural Properties while working to preserve buried remains he excavated.
Imazu was hired by the Archaeological Institute of Kashihara of the Nara Prefectural Government as a conservation scientist in 1989.
In 1998, the institute discovered 33 units of “Sankakubuchi Shinjukyo” or triangular-rimmed bronze “deity and beast mirrors,” decorated with images of gods and animals, at the Kurozuka Kofun tomb in Nara Prefecture.
The discovery aroused unprecedented attention from archaeologists and other specialists on ancient Japan because of the assertion by some experts that 100 bronze mirrors given to Himiko, queen of the Yamatai kingdom, by the court of Chinese Emperor Cao Rui in 238, were Sankakubuchi Shinjukyo.
With many researchers awaiting the release of data on the mirrors, it was going to take a few months to manually measure each mirror, given their complex design. Imazu thus turned to a 3-D measuring device, a new technology at the time, and shortened the process to eight hours. The machine also enabled him to find even microscopic scratches on the mirrors and minute differences in thickness between them.
Imazu then established a database for studies on bronze mirrors by measuring some 600 mirrors kept at Kyoto University, the Tokyo National Museum and the Imperial Household Agency.
Imazu transferred to the Kyushu museum in 2005 when he was 50.
“I wanted to bet on the new field of museum and conservation science in the 10 years I had until reaching mandatory retirement,” he said.
Unlike archaeological research institutes, museums display objects that have been unearthed to visitors. Imazu thought of creating a museum where visitors can “touch, feel and experience” cultural properties. He produced replicas of bronze vessels and clay pots with a 3-D printer but found that plaster and resin used by the machine tend to deteriorate when exposed to water and ultraviolet light.
Struggling to find a better way of producing replicas, Imazu came across Otsuka Ohmi Ceramics, which re-created the murals in the Kitora and Takamatsuzuka Kofun tombs in Nara using ceramic boards.
Ceramics are resistant to rain and ultraviolet rays and strong enough to withstand daily handling. Although the material shrinks by around 10 percent when baked, Imazu overcame the problem by having the 3-D printer produce a replica 10 percent larger than the original.
The replica of Kukai’s statue was made by taking 900 X-ray photos per minute with a large CT scanner. As the 3-D printer used was not big enough to produce a replica of the same size as the statue, the work was initially divided into nine parts.
The difference in height between the original statue and its replica is only about 1 cm.
Now that durable replicas can be made that bear an exact resemblance to their originals, Imazu foresees the day when his vision will come true and museum visitors will literally be able to “get in touch” with the past.
By subscribing, you can help us get the story right.