It is shown for the first time that a Fourier-transform infra-red spectroscopic study of cyanoacrylate fumed fingerprints provides a non-subjective confirmation of visual estimates of polymer deposition as made by fingerprint experts. The greatest degree of polymer deposition on latent prints within the parameters of the experiment were produced by prior exposure to ammonia followed by fuming with methyl cyanoacrylate monomer. The method with base activation also permits further quality enhancement of prints previously developed by the current method.