A printable flexible synthetic support bearing at least one authenticating or security marking. The support comprises: a synthetic substrate; at least one marking on at least one of the sides of the substrate, said marking consisting of at least one layer of a composition which alters the opacity of the substrate; and at least one layer of a printable pigmentary composition deposited on the marked side, and optionally on the unmarked side, of the substrate. The marking is invisible or barely visible in reflected light, but clearly visible in transmitted light. Applications in synthetic paper security.

Watermarked plastic support.

A document security system is provided by providing each document with a synthetic watermark, for instance using the process, compositions and apparatus disclosed in the aforementioned U.S. patent of Norris, et al and, within the perimeter of at least one of the symbols which is provided by the synthetic watermark, an identical complementary or otherwise corresponding symbol is printed using ink, paint, dye, stain or similarly contrastingly pigmented substance so as to create, in combination with the synthetic watermark a juxtaposition that can be looked-for as evidence that the document is genuine and its serial number unaltered.

Document bearing characteristic ink-printed indicia juxtaposed with corresponding characteristic synthetic watermark and method for producing same

L'invention concerne un support synthetique souple imprimable portant au moins une marque d'authentification ou de securite. Ce support comprend: un substrat en matiere synthetique, au moins une marque sur au moins l'une des faces du substrat constituee par au moins une couche de composition modifiant l'opacite du substrat, au moins une couche d'une composition pigmentaire imprimable deposee sur la face portant la marque et eventuellement sur la face du substrat ne portant pas de marque; la marque etant peu a non visible en lumiere reflechie et parfaitement visible en lumiere transmise. Application a la securisation de papier synthetique.

Support plastique filigrane

Paper is 'printed' with indicia using an unpigmented 'ink' that renders it translucent. For example, the 'ink' may be a mixture of varnish and oil, such as is conventionally mixed with a pigment to form ink for offset lithography. The paper may also be conventionally printed in register with the watermark effect.

Royston James Kerley

Papers

Paper with watermark effect