Patent ID: 8455087

Claim:
An infrared mark indicator comprising: an infrared reflective substrate; an image rendered on the substrate including a first metameric pattern formed from a first colorant combination alternating with a second colorant combination; a background rendered on the substrate including a second metameric pattern formed from a third colorant combination alternating with a fourth colorant combination; wherein each of the first, second, third, and fourth colorant combinations is formed from non-impact printing materials; wherein the first and third colorant combinations are a same visual color under normal illumination and the second and fourth colorant combinations are a same visual color under normal illumination; wherein the first and second colorant combinations are a different visual color under normal illumination and the third and fourth colorant combinations are a different visual color under normal illumination; wherein the first and second colorant combinations have a similar first infrared reflection under infrared illumination and the third and fourth combinations have a similar second infrared reflection under infrared illumination, wherein the first infrared reflection is dissimilar to the second infrared reflection; wherein a contrast in infrared light reflected at the substrate between the image and the background is detectable with an associated sensing device.