Patent ID: 7422158

Claim:
A system for printing an indicium on an item, the system comprising: a print head system adapted to print at least two different inks onto the item, the print head system comprising a first supply of a first ink having a first color under normal daylight and a second supply of a second different ink, the second different ink having a second color under a normal daylight which is substantially the same as the first color, and wherein the second ink comprises a fluorescent ink; and a controller for controlling application of the first and second inks by the print head system on the item, wherein the controller is adapted to print the first and second inks in at least partially intermixed patterns such that the patterns of the first and second inks are substantially visually indiscernible within the indicium in normal daylight, and the second pattern of the second ink is discernible from the first pattern when subjected to fluorescent-exciting radiation.