How artists networked before the internet is the focus of Little Black Books, an exhibition of artists’ address books at the Smithsonian’s Archives of American Art in Washington, DC (until 1 November). Joseph Cornell’s is stuffed with details of foreign pen-pals, even though he never travelled abroad, while Jackson Pollock and Lee Krasner’s records reveal the artists who frequented their house in East Hampton. But the best example comes courtesy of the textile designer Dorothy Liebes, who organised her contacts in categories such as “boys”, “extra girls”, “restaurants” and “Philadelphia”.