Preserved and enhanced holographic and optically variable devices and method for making the same

An optically variable device, comprising:

• an optically variable relief embossed on a polymer substrate or an embossable polymer layer;
• and
• a plurality of optical enhancer particles in a film of coating applied on said optically variable relief and bonded to the optically variable relief by a residual polymer bonded to the plurality of optical enhancer particles during their production, the film of coating having a thickness in a range between 10 and 30 nanometers or multiples of that range, a size of each of said plurality of optical enhancer particles in the film of coating being between 10 and 13 microns.

A method of enhancing an optically variable structure, comprising the steps of:

• providing an optically variable relief embossed on a polymer substrate or an embossable polymer layer;
• and
• forming a film with a thickness in a range between 10 and 30 nanometers or multiples of that range over the optically variable layer by applying a liquid coating to the optically variable relief, the liquid coating comprising an amount of a residual polymer bonded to a plurality of optical enhancers during their production and the plurality of optical enhancer particles of a size between 10 and 13 microns having an index of refraction differing by a minimum of ±0.2 from that of the polymer substrate or the embossable polymer layer, the amount of the residual polymer providing adhesion of the plurality of optical enhancers to the polymer substrate.