Showing papers on "Watermark published in 1972"
Patent•
23 Aug 1972
TL;DR: A document is protected against fraud by providing it with a stereoscopic pattern (a) in the form of design disposed below a plastics coating containing a prismatic screen which produces a stereoscopy image when viewed with the unaided eye or (b) in a couched blue watermark 3 1, Fig. 2, which is embossed with a printed red picture 4 1, the watermark and picture producing a stereo image.
Abstract: 1286309 Fraud preventing; pictures A KUFFERATH 20 Nov 1969 [21 Nov 1968 7 Oct 1969] 56945/69 Headings B6A and B6X A document is protected against fraud by providing it with a stereoscopic pattern (a) in the form of design disposed below a plastics coating containing a prismatic screen which produces a stereoscopic image when viewed with the unaided eye or (b) in the form of a couched blue watermark 3 1 , Fig. 2, which is embossed with a printed red picture 4 1 , the watermark and picture producing a stereoscopic image. when viewed with red/green spectacles.
3 citations