Books were both scarce and expensive items before Gutenberg invented printing with movable type in the late 15c. The number of copies of any text was always necessarily small. Before Gutenberg everything had to be written, the only means of reproducing being hands and pens. Men went to great lengths to acquire books: Benedict Biscop (d. c.690) travelled to Rome, much of the journey on foot, at least four times, returning on each occasion with books and relics. By the end of the 12c, the Benedictine monastery at Canterbury had a famous collection of 600 volumes. The *codex form required the skins of many animals, usually sheep, to use as folios, i.e. the pages. This was a principal item of cost. By the 14c there were professional copyists and illuminators, e.g. Luttrell Psalter. [< OldEngl. boc = something written, a charter, record]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.