Holographic tamper-evident label

Claim 1

A label providing a visual indication of an action taken with respect to an article comprising in combination: a first element made of a first material having a surface with a first surface relief pattern thereon, and a second element made of a second material having a surface with a second surface relief pattern thereon, wherein at least one of said first and second materials is transparent and said first and second elements are attached to each other at an interface including said first and second surface relief patterns resulting in a label without a pattern due to said first and second relief patterns, but are capable of being detached along said interface while maintaining the integrity of said first and second surface relief patterns, said first and second surface relief patterns are capable of forming visible images when separated and illuminated by light, said second surface relief pattern is a replica of said first surface relief pattern, and the refractive indices of said first and second transparent materials are such that said surface relief patterns will not form said visible images when said first and second elements are attached at said interface and will form said visible images when said first and second elements are detached, and further comprising an adhesive means for attaching said first and second elements to an article such that said action detaches said first element from said second element.