It is perhaps a strange link, but books, and the paper they were made of, could not becomes widely available until the wearing of underwear became commonplace. Inexpensive paper was made of cotton and linen rags, cut into small pieces and pounded into pulp by waterwheel powered trip-hammers. Worn out underwear was purchased by the rag and bone man and sold on to the paper mills.
Underwear began to be more widely worn, as trade revived and clothing began to be made of richer fabrics colored with exotic dyes, during the Renaissance. The cotton and linen underwear protected the expensive clothing from sweat stains and odors, in an era before detergents and chemical dry cleaning.
It is an odd thing, but the pages of that rare Renaissance book were probably a bra, undershirt, or petticoat in their first life.