Sales and auction catalogues of antiquarian booksellers and children’s book publishers, arranged alphabetically by seller’s name, as well as a small number of advertising leaflets. These catalogues were collected by the Opies (c.1950s-1980s), as well as by Roland M.J. Knaster (c.1920s-1940s). The Opies' catalogues often include pencil annotations referring to which sale items they were either interested in or had purchased, as well as cross referencing particular dates in the Opies' accession diaries.