“The development of literacy was certainly helped by the introduction of paper, which was made from rags,” says Dr Marco Mostert, a historian at the Centre for Medieval Studies, Utrecht University and one of the organisers of this year’s International Medieval Congress at the University of Leeds.
“These rags came from discarded clothes, which cost much less than the very expensive parchment which was previously used for books. In the 13th century, so it is thought, as more people moved into urban centres, the use of underwear increased — which caused an increase in the number of rags available for paper-making.” —From Rags to Riches, Or How Undergarments Improved Medieval Literacy (Alpha Galileo)
Filing this for a future “history of the book” unit. Via Language Log.