Restorers of ancient books work as "book doctors" at the National Library of China in Beijing. [Photo by Jiang Dong / China Daily]

The National Library of China is the country's top restoration clinic for precious ancient texts.

Nearly 20 "book doctors" work at the library, committed to making the valuable documents survive longer.

"The fragility of the books leaves little room for the introduction of modern machinery. The methods we use today are almost the same as we used in the old days," says Zhu Zhenbin, 52, who has worked at the library for the past 34 years.

The newly established National Museum of Classic Books is a part of the National Library of China, where about 2.6 million copies of old books are stored.

"Varieties of paper and binding methods used in ancient Chinese books make the process of restoration more complicated than Western ones," he says.

"It is like treating individual patients. It doesn't matter if we do the work slowly but it will be problematic if we lower our standards to accelerate our schedule," Zhu says.

"What we do is to make them survive longer." Workers admit that relatively recent issues, such as air pollution, keep popping up.

The restoration project also requires people with interdisciplinary knowledge, including in chemistry, the fine arts and ancient Chinese language. The museum will formally open to the public in September.