This article argues that in the fifteenth century, many manuscripts were physically recycled, and that this recycling is symptomatic of interest in sustaining books. In the case studies explored here, unwanted or old texts became valued for the physical qualities of the parchment on which they were written. Case studies of recycled manuscripts, including flyleaves, pastedowns, limp covers and palimpsests, are presented to argue that many books were made (and re-made) in sustainable ways. Alth...