Patent ID: 8789761

Claim:
A transaction card comprising: a card body adapted to substantially transmit radiation in a visible light wavelength region; said card body comprising an optically recognizable material selected from at least one of an infrared ink and/or an infrared film, wherein said at least one infrared ink comprises at least one infrared blocking dye and the same or different nanoparticles, wherein said at least one infrared film comprises the same or different nanoparticles and other metal oxide and/or non-oxide complexes sputtered on a substrate, wherein said at least one infrared ink and said at least one infrared film block transmission of incident infrared radiation, and wherein said same or different nanoparticles comprise a plurality of monodisperse particles having: a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology.