Patent ID: 7960688

Claim:
A photoluminescent marking comprising: (a) a photoluminescent layer comprising selected photoluminescent materials and, (b) one or more functional overlayers over the photoluminescent layer, wherein the marking emits fully or partially in the infrared region of the electromagnetic spectrum and wherein the one or more functional overlayers comprise at least one of: (i) selected colorant materials that adjust the daylight color of the marking to render it a stealth marking by either blending imperceptibly with the surrounding area of an object to which the marking is applied, or, when applied to objects that typically have non-photoluminescent markings for traditional usage, renders a daylight color indicative of such traditional markings, or (ii) selected colorant materials that increase the photolytic stability of the marking, or (iii) selected fluorescent materials that enhance the daylight observability of the infrared emission, or (iv) selected colorants to prevent the observability with the naked eye of a printed message that is printed on the photoluminescent layer or any of the functional overlayers (ii) or (iii) above.