Creation of a transparent window in a security substrate for security printing applications

Abstract

There is described a method of creating a transparent window (W*) in a security, especially paper, substrate () for security printing applications, the method comprising the steps of (i) providing a security substrate (), (ii) forming an opening (*) into and through the security substrate (), and (iii) filling the opening (*) with transparent material () thereby forming the transparent window (W*). The filling of the opening (*) with the transparent material () is carried out in a state where the opening (*) is open on both sides of the security substrate () and extends through the security substrate (), the filling of the opening (*) including the application of a first side (I) of the security substrate () against a supporting surface (A) of a supporting member () in such a way as to block one side of the opening (*), while the transparent material () is applied inside the opening (*) from the other side (II) of the security substrate (). Advantageously, the method further comprises the step of forming a field of lenses (L) on one side of the transparent window (W*), in particular by replicating the field of lenses (L) directly into the transparent material () filling the opening (*). Also described is a suitable device designed to fill the opening (*) with the transparent material ().