This paper examines the origins of inter-library loans in Australia in relation to special libraries. Prior to the advent of low-cost computing, union lists in special libraries were rare. In the early 1980's a number of serials union lists for health libraries were compiled that formed the basis for wider collaboration in inter-library loans (ILL). Gratis is a network of special libraries that formed on December 6, 1982, with 14 founding members. The immediate impetus to the formation of the group was the trebling of the cost of ILL. A small annual subscription funds a network now comprising over 250 special libraries in heath and allied fields, many of which are too small to participate in the national ILL network. Careful distribution of workload helps to facilitate participation among large and smaller libraries. This co-operative model has subsequently been adopted by law, emergency services, transport and government library networks in Australia and New Zealand. The paper will examine the origins of Inter-Library loans in Australia and the factors that gave rise to the Gratis libraries network, and its progressive adoption throughout Australia and the co-operative factors that distinguish GratisNet from the national ILL service.