Patent ID: 7703810

Claim:
A security device having opposing planar surfaces, which is suitable for use with any document or means of identification for authentication purposes, and which comprises: a first light-transmitting carrier substrate having a first optionally repeating pattern of indicia formed thereon, wherein the first carrier substrate is fixably attached to a second light-transmitting carrier substrate having a second optionally repeating pattern of indicia formed thereon, wherein the second optionally repeating pattern of indicia comprises at least one layer of a metal or metallic material, said pattern of indicia including areas free from metal or metallic material, wherein the first optionally repeating pattern of indicia is formed in part from a machine testable light absorbing material, and wherein the first and second patterns of indicia are used to authenticate a document or means of identification when the security device is used therein, wherein the patterns are different in form and color yet indistinguishable when the security device is viewed from either opposing planar surface.