Patent ID: 6837959

Claim:
A method for producing a tamper proof carrier of information, said method comprising the following steps, in order, (1) providing a two-layer assemblage comprising (i) a rigid sheet or web support, and (ii) a porous opaque ink receiving layer comprising a pigment and a binder whereby either the surface of said support, or the surface of said opaque layer carries a first set of printed information, (2) printing a second set of information, different from said first set, onto said porous opaque ink receiving layer by means of ink jet printing, (3) covering totally, partially, or pattern-wise the thus obtained assemblage with a UV-curable laquer composition, by means of coating, printing, spraying or jetting, whereby on penetration of the lacquer in said porous opaque ink receiving layer this layer becomes substantially transparent, (4) curing said lacquer composition by means of an overall UV exposure, thereby improving the adhesion between said support and said ink receiving layer, and the cohesive strength of said ink receiving layer.