The textual condition of the Romantic book unbound brings into focus the codex as an open-ended and unstable collection of book parts, restoring literature to a culture of ‘bibliodiversity’. A material culture approach shifts print paradigms to consider the altered codex as an assemblage of heterogeneous elements, an archive of materials that support and evidence practices of reading and collecting within emerging knowledge formations in the making. The bibliomaniac librarian Thomas Frognall Dibdin, the antiquarian draughtsman John Carter, the domestic printer Thomas Kirgate, the Shakespeare editor George Steevens, and the print seller, book maker, and autograph collector William Upcott provide a wider context for case studies on private press publications (Walpole), the artisanal printmaker poet’s invention and composition (Blake), and part publication in serial fiction (Dickens), arguing for a culture of illustration, instead of the later invention of the term ‘extra-illustration’, a back-formation born within a later media ecology of the book.