When does the thread-bound book appear?

Mid-Ming dynasty. Thread-bound book is the first time in the history of China binding technology that scattered pages are gathered together and bound into a book by means of bookbinding. /kloc-appeared in the mid-Ming Dynasty in the 5th century, which marked that China's binding technology entered a new stage. Thread-bound books refer to the types of books bound with thread, also known as ancient thread-bound, which is an important invention of working people in ancient China. The ancient paper books in China experienced two stages: scroll and album. The reel consists of coils, shafts, ribbons and belts. There were only books in this scroll form in the Han and Tang Dynasties. Song Dynasty is the era when book printing broke out, and various binding methods began to appear. Song Dynasty is the most important period of book binding form, and it is the period of great development and foundation of book binding form.