Method of embossing repeating patterns on a substrate, the patterns having different rates of repetition

摘要

In a preferred embodiment, a method of producing embossed first and second elongate, edgewise side by side, repeating, optical patterns on a sheet for use in producing secure identification means, the method comprising: continuously embossing the first and second optical patterns on the sheet, such that the first and second patterns repeat at different rates, so that the first pattern will "walk" with respect to the second pattern.