SUBSTRATE FLUORESCENCE MASK FOR EMBEDDING INFORMATION IN PRINTED DOCUMENTS

• Main Authors: BALA RAJA, ESCHBACH REINER
• Format: Patent
• Language: English
• Published: 15.11.2007
• Subjects: COLOUR PRINTING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; LINING MACHINES; PERFORMING OPERATIONS; PRINTING; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; STAMPS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; TYPEWRITERS

The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light, and yet decipherable under UV light. This fluorescent mark comprises a substrate containing optical brightening agents, and a first colorant mixture printed as an image upon the substrate. The colorant mixture layer has as characteristics a property of strongly suppressing substrate fluorescence, as well as a property of low contrast under normal illumination against the substrate or a second colorant mixture printed in close spatial proximity to the first colorant mixture, such that the resultant image rendered substrate suitably exposed to an ultra-violet light source, will yield a discernable image evident as a fluorescent mark.