| abstract |
A fingerprinting system comprising means capable of releasably retaining a liquid and a liquid composition releasably retained in said means, said liquid composition comprising a leuco color-former coupound, a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms, a substrate for receiving fingerprints associated therewith, said substrate being coated on at least a portion of one surface thereof with a color developing substance comprising a phenol/aldehyde condensation product produced by the reaction together of an alkyl-substituted salicylic acid, an alkyl-substituted phenol, and an aldehyde, said condensation product having been reacted with a metal source. |