Patent ID: 8505979

Claim:
A method of producing a data carrier with a marking, wherein the data carrier includes a laser-markable portion and a beam-modifying portion adjacent or over the laser-markable portion, the beam-modifying portion having a first optical property capable of modifying a laser beam according to a first manner, the method comprising: a marking step of irradiating a laser beam through the beam-modifying portion to allow the modifying of the laser beam according to the first optical property to produce a resultant laser beam that creates a marking with a visual impression corresponding to the laser beam modified according to the first manner at the laser-markable portion; wherein: the method further comprises, after the marking step, a modification step of modifying the beam-modifying property of at least a part of the beam-modifying portion through which the laser beam was irradiated for creating the marking so that the beam-modifying portion has a second optical property different from the first optical property in such a way that it is no longer possible to obtain exactly a laser beam modified according to the first manner at the laser-markable portion.