Richard F. Salant and Dawei Shen, Georgia Institute of Technology, Atlanta, Georgia, USA The early pioneer of research on elastomeric rotary shaft lip seals was the late Dr Ernest Jagger. During the 1960s, he demonstrated the existence of the lubricating film under the seal and proposed methods of load support and film control. Modern computing power has permitted a detailed theoretical study, much of which helps to confirm many of Jagger’s ideas. Research has now progressed to a stage where the shaft surface roughness can also be considered. This feature article, based on a paper originally presented at the International Sealing Conference, Stuttgart in September 2002, describes some of these studies.