A method for numbering, QR coding and/or barcoding of banknotes using laser writing

Abstract

A method for continuously or semi-continuously numbering, QR coding and/or barcoding of banknotes comprises the following steps: i) providing a substrate in form of a sheet of (security) paper or of a sheet of (security) polymer foil or a (security) composite comprising at least one security paper layer and at least one security polymer foil, ii) printing onto each of the two surfaces of the substrate sheet each one or more printing ink layers so as to generate a plurality of banknotes on the substrate sheet, wherein each printing ink layer extends over a part or the whole of the surface area of the substrate sheet, and wherein the printing ink of at least one of the printing ink layers comprises at least one pigment and/or at least one dye, which changes its color upon exposition to laser radiation, iii) curing the printing ink layers, iv) exposing the printed and cured (dried) substrate sheet to laser radiation so as to create one or more features selected from the group consisting of individual numbers each comprising at least two numerals and optionally one or more characters, of individual QR codes, of individual barcodes and arbitrary combinations of two or more of the aforementioned features on each banknote of the printed substrate sheet, wherein all of the one or more individual (serial) numbers, of the one or more QR codes and of the one or more barcodes are generated by the exposure to the laser radiation, and v) cutting the printed substrate sheet obtained in step iv) to individual banknotes.

Dependencies are inferred from the claim text.