Giving Terracotta Warriors a fighting chance

Conservators and restorers have made continuous innovations in science and technology applications over the past few years in China to show cultural relics in a new light, literally, and help traditional culture shine with a greater vitality. With modern technology and equipment preserving the true colors of cultural heritage, now people can better appreciate history.

A 3D-printed replica of a green-faced Terracotta Warrior from the Qin Dynasty (221-206 BC) at the Emperor Qinshihuang's Mausoleum Site Museum recently attracted a large and appreciative audience at an exhibition in Chongqing, Southwest China.

The exhibition, Crafts First: Technology and Equipment for Cultural Relics Preservation, kicked off on Sept 27 and showcases technologies and equipment used in the prevention of damage, protection, research and management, as well as the use of cultural relics. It is said to be the first of its kind in the country. The exhibition will last three months.

The new knowledge and technologies have been used on the Terracotta Warriors and Horses, part of the funeral objects from the tomb of China's first emperor, Qinshihuang (259-210 BC), which is widely known in China as the Eighth Wonder of the World.

The mausoleum, including the pits of the Terracotta Warriors and Horses in Xi'an, capital of Shaanxi province, was placed on the UNESCO World Cultural Heritage list in 1987.

In recent years, the National Cultural Heritage Administration has attached great importance to preservation equipment for cultural relics.

After more than 10 years of development, the overall support and service offered by cultural relics protection equipment has greatly improved, boosting the development of cultural heritage, according to Li Qun, director of the administration.

"China has achieved the integration of technology and specialized equipment, industrial application and service-oriented manufacturing in the field of cultural relics. Protection equipment has become an indispensable measure in the use and passing on of cultural relics," he said at the Seminar on Cultural Relics Protection Technology and Equipment on Sept 27 in Chongqing.

"We have achieved major breakthroughs in protecting our cultural relics and some of our technology and equipment is among the best in the world."

The original Terracotta Warrior, on which the replica on show is based, was unearthed from pit No 2 in the Qinshihuang Mausoleum. It is the only one with a green face and is highly valuable for archaeological research, according to deputy curator of the museum Zhou Ping.

Zhou said that to showcase the green-faced Terracotta Warrior - half-kneeling and painted in green and red - to the public, the museum came up with the idea of promoting a replica by utilizing achievements in archaeology, materials science, arts and crafts, as well as new digitalization technology, such as spectrum analysis, high-definition scanning and 3D printing.

She said that almost all original restored figures will be put back where they were in the tomb, but a few with well-preserved colors will be stored in laboratories and warehouses, among them the green-faced one.

To preserve the pigments on the Terracotta Warriors and Horses, experts at the museum now use polyethylene glycol, or PEG film, formed by electron beam irradiation to reinforce and secure the raw paint. Moreover, the full preservation chain starts as early as excavation, with equipment on-site analyzing the material composition.

Research findings also show that, the color Chinese purple, which is unique in the world, was found on the Qin Terracotta Warriors. Chinese experts have discovered that the color mainly consists of synthetic barium copper silicate pigments. There are a dozen more colors on the Qin Terracotta Warriors and Horses such as cinnabar red, azurite blue, malachite green and antique white. On top of this, the exhibition deals with matters beneath the surface.

Models of the manned submersible Shenhai Yongshi, or Deep Sea Warrior, and its carrier - China's scientific research vessel Tansuo 1 - for the exploration mission involving two ancient shipwrecks in the South China Sea, probably dating back to the middle of the Ming Dynasty (1368-1644), were also displayed.

"I think our ultimate goal is not to satisfy the archaeologists' curiosity, but to finally showcase the relics to society," said deputy director of National Centre for Archaeology Sun Jian at a forum related to the exhibition on Sept 26 in Chongqing.

A leading underwater archaeology expert in China, Sun shared thoughts on the underwater protection of individual cultural relics at the forum. He said it takes decades to excavate a shipwreck site, and with specially designed cutting-edge equipment and materials, it can be protected and restored underwater, under the Convention on the Protection of Underwater Cultural Heritage.

According to Zhou Yang, curator of the exhibition, the exhibition showcases a total of 64 cultural relics preservation technologies and equipment used in 19 scenarios, including unmanned and archaeological sites, caves, grottoes, restoration rooms and laboratories.

"I feel very proud that all the technologies and equipment are domestically developed," said the curator, who is also deputy curator of the China National Silk Museum.

A representative of R&D in the field, Zhengzhou Fenghua Industry Co has brought two sets of equipment to the exhibition. One is a high-definition photo shooting and restoration table, and has not only been used across the country, such as at the National Library of China, Henan Museum, Nankai University Library and Tianjin Library, but has also been introduced to the United States and Canada. The table can greatly improve the restoration of ancient books, calligraphy and paintings, said Ma Weili, CEO of the company.

The equipment, which has an LED flat light source under the glass tabletop, can clearly illuminate unfolded paper for copying, restoration and observation. Its high-definition monitoring and recording functions can reduce the difficulty of restoration and help restorers or trainers conduct remote teaching.

The company is working to play a part in the international preservation and restoration of ancient books. Its North America subbranch FH Conservation has recently participated in setting a standard in the field in the US.

"Besides presenting the exhibition to the public, we hope to attract more high-tech enterprises to the realm of cultural relics, which we believe is a real blue ocean market (a new market with little competition or barriers)," the curator said.