This collection is largely comprised of correspondence concerned with printing, but letters are also of a personal nature. Correspondents include: Edward Lee Stone, Melbert B. Cary, Jr., E.W. Johnson, Carl Dair, Mary Ethel Somerville, along with carbon copies of a letter from Duff to Edward Lee Stowe, and two letters to Carl Dair. There is also one letter to Blake from William Colgate sending him a copy of Horace Walpole on Milton, along with a typed copy of Duff's reply. The collection also includes a visitors' book at Cooneen Cross, proofs of Duff's The Printer of the Jesuit Relations and a a carbon copy of Duff's Ben Franklin and the First Printing in Montreal.