

The book binding process varied and became more complex as the Middle Ages progressed. I will give just a brief explanation of the basics.
After the pages were collected from the scribes, they were folded into groups called gatherings and lined up in order. Then holes were cut through all the sheets and the pieces were sewn together (shown above) with cords or leather. Next, those were attached to the wooden boards that made the covers of the book. Then those wooden boards were covered with leather or fabric and decorated, sometimes very ornately.
Books were rare since everything was hand-copied, hand-bound, and hand-decorated with the use of very little machinery. They were usually ordered specially by wealthy patrons or made and kept in monasteries. They ranged from simple books on parchment with plain leather coverings to delicate vellum pages with jeweled and gold-inlay covers.
Sources: http://web.ceu.hu/medstud/manual/MMM/bookbinding.html













