This dissertation engages with the production and use in late medieval England (c.1200–c.1500) of manuscript codices copied, in whole or in part, on offcuts: cheap, low-quality parchment scraps created as a byproduct of parchment manufacturing. After presenting a method for identifying offcuts, it explores the material through statistical techniques and case studies. Applying this mixed methodology to a corpus of 140 offcut-bearing production units spread across 75 handwritten books, it delineates a range of manuscript production stages, examining the sociocultural contexts of books recruiting offcuts as writing support. The dissertation pursues this study in four chapters. Opening with a terminological discussion, chapter one describes medieval parchment-making, clarifying how offcut traits arose during manufacture, distinguishing offcuts from similar types of parchment, and describing medieval uses for offcuts. Chapter two discusses quantitative codicology, justifying the mixed quantitative–qualitative approach, then delineates its dual-stage methodology: (i) establishing offcut diagnostic traits via linear regression analysis; (ii) assembling the corpus and analyzing it via a descriptive statistical lens. It finishes with an overview of the analysis’ main findings, noting that the corpus is dominated by Fachliteratur; lacking in texts often regarded as ‘popular’ (e.g., vernacular romances); and largely copied for personal consultation in professional, educational, or domestic contexts. Chapters three and four take up the primary subcorpora—one comprising common law books; another, miscellaneous, but chiefly theological and medical, provisionally sorted based on the medieval division of disciplines, quadrivium and trivium—engaging each via descriptive statistical overviews and case studies of representative books: London, British Library, Harley MS 912, Harley MS 1261, Harley MS 6644; Oxford, Bodleian Library, MSS Ashmole 1378, Digby 2, Digby 24. / Graduate / 2023-09-09