Patent ID: 8293450

Claim:
A coating layer comprising: a polymer matrix, wherein matrix is a UV-curable matrix selected from UV-curable monomers, UV-curable oligomers, and mixtures thereof, and a photoinitiator; and a labeling dye, wherein the labeling dye absorbs electromagnetic radiation in the visible range of about 400-700 nm to provide visible coloration, wherein the labeling dye has a characteristic to form a reaction product upon exposure to radiation energy at a wavelength of about 400-900 nm, wherein the product has a color different than the labeling dye or is colorless, and wherein the coating layer does not include a solid phase; wherein the labeling dye is selected from: 1,1′-dibutyl-3,3,3′,3′-tetramethylindadicarbocyanine hexafluorophosphate, 4,5:4′,5′-dibenzo-1,1′,3,3,3′,3′-hexamethylindadicarbocyanine perchlorate, 1H-benzindolium, 2-[7-[1,3-dihydro-1,1-dimethyl-3-(4-sulfobutyl)-2H benzindol-2-ylidene]-1,3,5-heptatrienyl]-1,1-dimethyl-3-(4-sulfobutyl)-, inner salt, 3,7-bis(diethylamino)phenoxazinium perchlorate, 4,5-benzo-1,1′-dibutyl-3,3,3′,3′,5′-pentamethylindacarbocyanine perchlorate, and combinations thereof.