Patent ID: 7188774

Claim:
An apparatus for printing a succession of unique composite indicium on a substrate useful for uniquely labeling each article in a series of articles, the apparatus comprising: a feed mechanism for feeding a sheet substrate having a first location and successive locations through said apparatus; a first printing cylinder that prints indicium having a first pattern at said first location and at said successive locations on said sheet substrate, said first cylinder having a first diameter for printing on said substrate; and a second printing cylinder that prints a second indicium at said first location and at said successive locations, said second indicium comprising a fixed second pattern, said second printing cylinder having a different diameter for printing on said substrate at said first location than said first cylinder diameter for printing at said first location in order that said first and second printing cylinders function out of phase, the combination of said first indicium and said second indicium at said first location and each said successive location comprising a unique composite indicium.