The papers comprise correspondence, diaries, notebooks, drafts, minutes, reports, cuttings, printed items, photographs, tape recordings and films. There are a few letters, references and printed works dating from Lake's early life, but most of the papers date from the late 1940s onwards. They document the later years of his long service with the National Library and in particular his work as the Liaison Officer in London and Chief Selection Librarian. There is also material of both an official and private nature relating to Australian films. The later papers deal with Lake's life in Balmain and his strong concern with environmental matters. Finally, there are a large number of letters from his mother and children.