Improvements in security documents

摘要

A method of manufacturing a security document comprising the steps of providing a transparent plastics substrate, applying a radiation curable ink directly to at least side of the substrate and simultaneously embossing and curing with radiation different regions in the same area of the ink on one side of the substrate with at least two different embossed relief structures, each forming a different type of diffractive security element integrated within the same area to form a composite security device.