摘要 |
The invention relates to a document of value consisting of a substrate of predetermined surface area with a printed image visible to the naked eye and a marking in the form of characters, patterns or the like at least partly superimposed on the printed image. The marking is represented by a feature substance having at least one mechanically detectable physical property and extends over the predominant part of the surface of the document. The marking additionally has a given measurable regularity which makes it possible, by mechanical scanning of the marking, to detect the correctness of the distribution and recognize gaps or added partial elements of other authentic documents as disturbances.
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