Patent ID: 8622555

Claim:
A security laminate, comprising: a transparent binder layer; a first plurality of retroreflective microspheres in a first area, the first plurality of retroreflective microspheres comprising dry retroreflective microspheres having a refractive index between about 1.65 and about 2.10; and a second plurality of retroreflective microspheres in a second area, the second plurality of microspheres comprising wet retroreflective microspheres having an index of refraction of between about 2.0 and about 2.6; wherein the first plurality of retroreflective microspheres and the second plurality of retroreflective microspheres protrude from the binder layer; wherein a retroreflective brightness of the first plurality of retroreflective microspheres is greater than a retroreflective brightness of the second plurality of retroreflective microspheres under a first medium that exhibits a refractive index between 1.00 and 1.20; and wherein a retroreflective brightness of the second plurality of retroreflective microspheres is greater than a retroreflective brightness of the first plurality of retroreflective microspheres under a second medium that exhibits a refractive index between 1.25 and 1.35.