Patent ID: 8840983

Claim:
An object comprising: a substrate having an indicia thereon, wherein the indicia comprises a first layer having a first fluorescent chromophore which emits fluorescent radiation in response to ultraviolet (UV) illumination, a second layer comprising a photochromic material, wherein the photochromic material has a first optical appearance without UV excitation and a second optical appearance after receiving UV excitation, a third layer comprising a second fluorescent chromophore which emits fluorescent radiation in response to UV illumination, wherein the first, second, and third layers are present in this order on the substrate, wherein the indicia appears to radiate a first color that is based on the mixed fluorescence radiation from the first fluorescent chromophore and the second fluorescent chromophore, the indicia appears to radiate a second color upon continued UV excitation as the second layer has changed to the second optical appearance, the photochromic material attenuates the fluorescent radiation from the first fluorescent chromophore in the second optical appearance, the photochromic material changes from the first optical appearance to the second optical appearance while under UV excitation over a period of more than one-third second to less than 20 seconds such that the first color is visible for at least one-third second to as long as 20 seconds, and the second color is based on fluorescent radiation from the second fluorescent chromophore.