Device for creating multitone watermarks and methods of manufacture and use thereof
US8840756B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2012 |
| Grant date | Sep 23, 2014 |
| Priority date | — |
| Expiry date | Sep 24, 2032 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F11/006
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to the field of paper and relates to a sheet including a high-definition high-contrast multitone watermark having areas of pronounced brightness. Such watermark is particularly obtained by means of a part (4) including a surface (5) having a raised area and perforations (6). The perforations (6) are such that making the cross-section thereof, at a given distance from the draining surface, directly depends on said distance. The present invention also relates to the method for manufacturing said part that is used for forming one such watermark, to the part itself, and to the use of said part when forming a watermark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.