The contact of human fingers with solid surfaces and their subsequent separation have been studied microscopically. Scanning electron microscopy and contact angle measurements have been applied to examine the deposit film. When a finger touches a surface, a film of liquid present on the finger spreads to produce apparent contact over much of the fingerprint ridge area. Lifting of the finger causes the film to recede and leave a deposit which may be either a distribution of droplets on a thin contaminating layer of adsorbed molecules, or a continuous film: which type is dependent on both the composition of the fingerprint and the nature of the substrate.