SECURITY SHEET OR DOCUMENT HAVING ONE OR MORE ENHANCED WATERMARKS Russian patent published in 2019 - IPC G07D7/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to a security sheet or document having one or more enhanced watermarks. In one typical embodiment, the inventive security sheet or document is a single-ply paper that is made up of a paper layer including one or more watermarks, and a micro-optic security device (e.g., a patch or thread) that at least partially covers an upper or face portion of the watermark(s). Overlying patch or thread increases the durability of the watermark(s), thereby allowing for the watermark(s) as well as reduced fibre density areas therein to be made larger, and further allowing for the reduced fibre density areas to be made thinner. In a preferred embodiment, the micro-optic security device projects one or more synthetic images that coordinate or link in with the watermark design(s). In a more preferred embodiment, the micro-optic security device offers a machine detectable/readable feature in the form of enhanced IR-brightness, especially when measured in transmission.

EFFECT: as will be readily appreciated, the inventive security sheet or document offers greatly improved counterfeit-resistance.

12 cl, 11 dwg