Patent ID: 7396557

Claim:
A method for forgery-proof marking of objects, comprising a) applying an inert second layer ( 3 ) to a first layer ( 1 ), wherein said first layer ( 1 ) reflects electromagnetic waves, wherein said second layer ( 3 ) has a predetermined thickness, is transmissive for electromagnetic waves, and is made from a polymer selected from the group consisting of a polycarbonate (PC), a polyethylene (PE), a polypropylene (PP), a polyurethane (PU), a polyimide (PI), a polystyrene (PS), or a polymethacrylate (PMA); b) applying a third layer ( 4 ) to said second layer ( 3 ) to thereby generate a label, wherein said third layer ( 4 ) is formed from metallic clusters, wherein, due to an interaction of light reflected from the first layer ( 1 ) with the third layer ( 3 ), the label appears colored, the color depending upon the angle of incidence or angle of observation; and c) connecting said label to said object.