US Patent 11691449 Processes for producing optical effects layers

The present invention relates to the field of and processes and printing apparatuses for producing optical effect layers (OEL) comprising magnetically oriented platelet-shaped magnetic or magnetizable pigment particles on a substrate. In particular, the present invention relates to processes using printing apparatuses comprising a first magnetic-field-generating device mounted on a transferring device (TD) and a static second magnetic-field-generating device for producing said OELs as anti-counterfeit means on security documents or security articles or for decorative purposes.