摘要 |
The security marking for security documents, in particular papers representing a value, consists of a plurality of circular or elongate holes (11), which are arranged in parallel rows (14) in a printed area (5) of the document. The diameter (a) of the holes is chosen such that they are practically invisible with bare eyes in reflection, but become well visible when the document (10) is held against a light and viewed in transmission. The holes (11) are generated by laser pulses. The marking can be produced quickly and easily and it can be verified without technical aids. |