Method for producing marking on substrate for printing product, involves applying adhesive on substrate, which has marking element which is not observable with naked eye

摘要

The method involves applying an adhesive (3) on a substrate (1), which has a marking element (6) which is not observable with the naked eye. The substrate is brought in contact with the transfer film. The coating material is incompletely transferred from the transfer film to the substrate by formation of coincidental defects (5,5a,5b,7,8). The marking element is a nanoscopic or microscopic marking element. Independent claims are included for the following: (1) a method for authentication of printing products; (2) a method for inspecting the quality of printing products; and (3) a printing substrate processing machine, particularly a sheet-processing rotary printing press for lithographic offset printing or a long direction web-fed rotary printing press for executing one of the methods.