摘要 |
This invention relates to a document authentication concept wherein a transparent tape having encoded text thereon is applied to the document. The encoded text printed on the transparent tape is printed with invisible ink so that the message thereon is not visible to the unaided eye. Preferably, the ink is visible in the infrared range. With such a combination, the authentication medium can be applied to a document that has a predetermined format so that the tape can be placed over a portion of the text and the latter will still be readable.
|