http://sciencefair.math.iit.edu/projects/fingerprints/fingerprint1.jpgLatent Fingerprint: a fingerprint made by deposits of oils and/or perspiration, not usually visible to the human eye. Various technologies, including lasers, can be used to identify latent prints.
Direct fingerprints: prints taken for usually identification purposes
Plastic Fingerprints: these occur when the finger touches or presses against a plastic material in such a way that a negative impression of the friction ridge is produced. These types of prints are generally found in places like a newly painted object, wax from candles or sealants, in the gum on envelopes and stamps, on substances that melt easily or soften when they are held in the hand. An example of this would be chocolate.
http://technologyinterface.nmsu.edu/summer97/security/finger.html
http://edwardh.se/www.edwardh.se/images/reviews/mh36/pb-fingerprints.jpg
