Method for producing a pattern on a substrate using security ink

摘要

The method involves marking a layer that is sensitive to laser radiation, with a laser beam by ablation of the sensitive layer at beam impact points on the sensitive layer for forming a predefined thickness profile such that the profile generates a luminous intensity modulation reproducing a pattern (24) observable through a safety ink layer at a predefined wavelength. The safety layer is formed from a material comprising a liquid crystal ink e.g. OASIS(RTM: complete line of water based ink), optical variable ink(RTM: anti-counterfeiting ink), or iridescent ink. An independent claim is also included for a safety document comprising a support.