Paper including a multitone-effect watermark, and a wire for manufacturing the paper
AssigneeArjowiggins Security
InventorsStephane Mallol, Yvan Thierry
Life of this patent
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Abstract
Paper based on a fiber composition and having at least one multitone-effect watermark. When observed in transmitted light, the watermark has a set of pale zones arranged in the manner of a screened image.
Claims14
Paper based on a fiber composition, the paper comprising at least one multitone-effect watermark, wherein the watermark, when observed in transmitted light, has a set of pale zones arranged in the manner of a screened image.
A wire used in the wet stage of papermaking, the wire being provided with a set of masks representing a pattern to be made as a multitone-effect watermark on the paper, the set of masks being denser in regions corresponding to the pale portions of the looked-for watermark and less dense in the regions corresponding to the other portions of the looked-for watermark.
A method of making a screened image for forming a watermark, the method comprising the following steps:
- making a screened image from a scanned image by using a known screening method;
- making a perforated element from said screened image and suitable for use during the aqueous stage of paper formation, said perforated element having solid regions disposed like the pale portions of the watermark;
- and
- making a watermark by means of said perforated element by placing the perforated element so that it limits accumulations of fibers in register with the solid regions of the perforated element during the aqueous stage of paper formation.
Dependencies are inferred from the claim text.