Rare Books and Ancient Writings Some of the earliest "books" were created in ways that were unique to China, either on silk or on thin strips, or slips, of bamboo or wood. These slips were laid out in a specific order and bound together using hemp or silk threads. The invention of paper in China, probably during the first century C.E.., provided a more versatile medium for writing. The invention of woodblock printing, during the Sui (581-618) and Tang (618-907) dynasties, and the subsequent refinement of printing technologies, culminating in the development of movable clay type by Bi Sheng between 1041 and 1048, led to the popularization of the book in China. From the late Ming (1368-1644) through the early Qing (1644-1911) dynasty, the printing industry underwent a period of great development. A broad range of books was produced to meet popular demand, including newly written fiction and drama, encyclopedias, poetry and literature anthologies, instructional books on writing and art appreciation, works on science, medicine, and archaeology, and reprints of many great classics. Developments related to production included cheaper paper and simpler character fonts that required less woodblock carving, which in turn meant shorter production time. Many regional bookshops and printing houses became known for the types of books in which they specialized. The National Library of China's collection of rare books and ancient writings numbers close to 300,000 volumes.