Abstract: A flexible packaging material, especially a seal and/or packing material which can be sterilized, having a single film or a film composite with a single or double-print motif. The packing material contains a partially or fully transparent, heat-resistant cover layer applied to at least the print motif by an electro-photographic method. The cover layers are produced from an ultraviolet radiation or electron radiation hardening toner.

Abstract: A method for optimizing colored images emitted by a color printer on the non-white surfaces of substrates and for optimizing the amounts of printing ink used, wherein an image motif is processed by a computer-assisted image processing system in order to form a master copy which is ready for output. The method determines, for each pixel, whether and with what color density, a white underprint can be applied to a corresponding pixel, using an algorithm based on overall color density SF. The surface of the substrate is thus only underprinted with white on the pixels of the master copy where the overall color density is lacking or low.