Metal effect pigments coated with additives for nanometallography printing

A method of printing onto a surface of a substrate, which method comprises

• a. Providing a donor surface
• b. Passing the donor surface through a coating station from which the donor surface exits coated with individual particles, and
• c. Repeatedly performing the steps of
• i. Treating the surface of the substrate to render the affinity of the particles to at least selected regions of the surface of the substrate greater than the affinity of the particles to the donor surface, wherein a receptive and/or adhesive layer is applied onto the substrate,
• ii. Contacting the surface of the substrate with the donor surface to cause particles to transfer from the donor surface only to the treated selected regions of the surface of the substrate, thereby exposing regions of the donor surface from which particles are transferred to the corresponding regions on the substrate, and
• iii. Thereby generating a plurality of individual particles adhered to the treated surface of the substrate,
• iv. Returning the donor surface to the coating station to render the particle monolayer continuous in order to permit printing of a subsequent image on the surface of the substrate,
• characterised in that at least 50 wt. % of the individual particles are flaky metal pigments comprising a flaky metallic substrate and a surface modification layer of the metallic substrate, wherein the surface modification has been made by a treatment of the metallic substrate surface by at least one of the modification substances from the group consisting of phosphate ester, phosphonic esters, phosphonic acids, phosphinate esters, organofunctional silanes, organofunctional titanates, organofunctional zirconates, organofunctional aluminates and mixtures thereof.