| abstract |
A printing system for printing a security feature in the form of a latent image comprising at least three compositions (RI), (C1) and (C2): (RI) a reactive ink comprising a silane compound (A) comprising at least a first and a second polymerizable moiety which are different from each other and are polymerizable by different mechanisms, loaded in a first reservoir of a first printhead, (C1) a first catalyst composition comprising a substance able to react with the silane compound (A) of composition (RI) and promote the polymerization of the first polymerizable moiety, loaded in a second reservoir of said first printhead or of a second printhead, (C2) a second catalyst composition comprising a substance able to react, alone or in presence of composition (C1), with the silane compound (A) of composition (RI) and promote the polymerization of the second polymerizable moiety. |