Engraving sheet structure

摘要

An engraving sheet structure suitable for use as sheets of, for example, a passport or a bankbook has a substrate made of a plastic sheet made of, for example, a bi-axially orientated high-density polyethylene sheet having an opacity degree not greater than 70%, and an engraving layer formed on the substrate and having an opacity not less than 40% and made of a material which contains a cross-linkable binder. The opacity of the substrate is lower than that of the engraving layer, the difference in the opacity being not less than 30. The engraving layer being adapted to be engraved to form an image from its surface down to the level of said substrate. One or more colored layer may be provided between the substrate and the engraving layer.