This is just out of curiosity?

Question

How long can fingerprints survive if no one disturbs them? I mean, can they last forever?

Answer 1

A rather long time, as the oils act as a kind of protection

Answer 2

Q: Can you tell me how long fingerprints stay on or last? (Didi, Johannesburg, South Africa)

A:  Fingerprints typically last for years, but how long depends on what kind of surface the fingerprints are on and whether or not they've gotten wet.

"Fingerprints on paper, cardboard and unfinished wood can last for up to forty years (per actual casework histories), unless exposed to water," says Ed German, "one of the world's leading fingerprint experts" according to FBI and Department of Defense top management members quoted in The New York Times.

Typical fingerprints (i.e., sweat from skin ridges covering the fingers, palms, soles and toes) can "even survive fire," German e-mails from his home in Newington, Virginia. That is, if the prints are not completely charred.

"Fingerprints on non-porous surfaces such as plastic, metal and glass can last for many years, also, if not exposed to water and if left undisturbed," German says.

"Undisturbed" seems critical. Investigators err by putting a gun, glass or bottle in a plastic bag, for example. Contact with the plastic bag can destroy latent prints. "It's about the same as wiping it [the gun] clean in many instances," German admonishes. Picking up a glass with a handkerchief is just as bad. Picking up paper with a handkerchief, however, is harmless. The fingertip's sweat secretion (not oily, by the way) has soaked down into the paper fibers, safe from destruction.