Security at its Best

Holograms: Clear security beyond the silver rainbow

Eye-catching holograms are one trend that blurs the line between decorative and security packaging. Today they can be found on everything from toothpaste boxes, to snazzy computer games, and bottles of car oil to bottles of beer. Eric Bartholomay, product development manager at Toray Plastics (manufacturers of polypropylene and directly-embossed polyester films), states that holograms such as these (decorative) are usually embossed into film, which is then metallized—leaving it with the shiny silver look. However, in security applications the hologram is instead coated with a high-refractive index (HRI) coating (typically a zinc-sulfide), allowing the printer to further process the embossed hologram and still see it, and any printing underneath.