A series of six diary notebooks, recording book accessions, including titles, authors and publishing dates, as well as the date of purchase, the source of acquisition, such as the name of bookseller, auction, or person who gifted the item, and price paid. The diaries also include Peter Opie's notes about his various purchases, as well as his reflections on the subject of book collecting. The second to fifth volumes include booksellers' contact details at the back. Various papers are inserted, including extracts from sales catalogues, receipts and letters from booksellers.