Method of making tamper-evident structures

摘要

The method involves forming a laminate capable of generating a substantially non-dichroic color by a light interference and absorption phenomenon by depositing a layer of a metal of medium light reflectivity by a vapor deposition technique on a suitable substrate, anodizing a surface of the metal in the presence of fluorine ions to form a detachable film of an oxide of the metal on the surface having a thickness suitable for color generation, and adhering a flexible strip of transparent or translucent material over the oxide film in such a manner that the strength of attachment of the flexible strip to the oxide film exceeds the adhesive strength between the oxide film and said surface of said metal.