Patent ID: 7380500

Claim:
A process for the offset printing of a receiving medium with a functional pattern comprising in any order the steps of: applying a printing ink to a printing plate and wetting said printing plate with a fountain comprising a fountain medium comprising between 50% by weight and 100% by weight of water thereby providing said printing plate with an area inked with said printing ink and an area coated with said fountain, and transferring said printing ink and fountain onto said receiving medium, wherein said fountain further comprises as a solution or a dispersion in said fountain medium at least one moiety having at least pH-indicating, whitening, fluorescent, phosphorescent, X-ray phosphor or polymeric intrinsically conductive properties, wherein said moiety having at least pH-indicating, whitening, fluorescent, phosphorescent, X-ray phosphor or polymeric intrinsically conductive properties is a polymer or copolymer of a 3,4-dialkoxythiophene in which the two alkoxy groups may be the same or different or together represent an optionally substituted oxy-alkylene-oxy bridge, a functional pattern of said at least one moiety is provided on said receiving medium, and a pH-indicator pattern is provided when said fountain comprises at least one moiety having at least pH-indicating properties.