Contrast enhancing marking system for application of unobtrusive identification and other markings

摘要

A method and a system is disclosed for affixing invisible or unobtrusive markings to mail pieces (4), and subsequently collecting information from the mail pieces for sorting purposes. The system includes the affixation of an optically contrasting layer (1) to a mail piece, the layer changing optically upon the application of a stimulus to present a contrasting background for imaging encoded information (3) applied over the layer and related to the mail piece.