Five years ago, a documentary series titled "Masters in Forbidden City" was released in China and soon became a hot-button topic on social media, bringing the profession of cultural relic restoration into the public spotlight.

Given China's long history and rich collections of ancient artifacts from various dynasties, it takes meticulous hands, years of experience and a thorough understanding of history to become a qualified restorer. As backstage heroes, many of them have dedicated their lives to preserving national treasures.

Some restorers deal with heavy objects such as bronzeware, others are good at fixing things as light as a piece of paper.

For around four decades, a desk lamp, a plate of adhesive paste, and a brush have constituted the basic equipment of Wang Jinyu's daily work.

Wang, 59, is an ancient book restorer at the Tianyige Museum in the city of Ningbo, in east China's Zhejiang Province. Tianyige is the most ancient private library in China, built in the 1500s, preserving over 300,000 volumes of ancient books. Many of the books need careful maintenance or repair due to aging, being moth-eaten, cracking and other damage.

Restoration starts with selecting the right paper. The museum offers nearly 300 types of paper of different colors, thicknesses and textures, and a restorer has to find the one most similar to that of the original book.

After disassembling, dusting and flattening the pages to be fixed, the restorer tears a patch from the selected paper, dips it in paste and carefully sticks it to the back of the page to cover the hole. Then any extra material is trimmed bit by bit until the page is restored.

The process may sound simple, but it is time-consuming in practice. In Wang's opinion, a qualified restorer has to be calm, careful, patient and perseverant. "We would sit there for hours just to cover a tiny hole," she said.

In 2018, Wang led a team of colleagues in restoring a set of 58 books published around 200 years ago, of which 19 were so damaged that their pages could not be turned.

"We had to race against time to rescue them, or it would be too late," recalled Wang. The team finished the restoration in a little over two years, with satisfying results that were acknowledged by experts in the field.

For younger staff in Tianyige, Wang is a role model they look up to. But for Wang herself, the road to perfect craftsmanship is endless.

"Every book is different. I will always encounter new challenges and obtain new experiences. There will never be a day when I'd say 'I've learned and done enough,'" she said.