A book from 1633 that was previously considered too fragile to open has been digitized and unveiled by the Cambridge University Library.

The Manual of Calligraphy and Painting (Shi Zhu Zhai Shu Hua Pu) is part of the library’s Chinese collection. It was made by the Ten Bamboo Studio using a technique called polychrome xylography, which was invented by printmaker and owner of the studio, artist Hu Zhengyan.

To create an image using polychrome xylography (also known as douban), requires the use of several different printing blocks, each with a different hue of ink to create the watercolor effect. It was a pioneering technique at the time.

The 17th century book contains 138 paintings and drawings with supplemental texts and poetry from 50 different artists, as well as instructions on basic skills. Topics range from calligraphy to flowers, birds, rocks, and fruit.

The Manual of Calligraphy and Painting was in print for over 200 years, and while it’s been reprinted several times, an early edition is very rare today. The book’s butterfly binding—one of the hallmarks of its age—was also the reason researchers were afraid to open it previously. Its fragility caused concern that opening the manual would do irreparable damage.

The library also added a slew of other items from its Chinese collection to the digital library (including Chinese Oracle Bones), which are well worth checking out.

All images via the University of Cambridge Digital Library

[h/t Colossal]