| 摘要 |
<p>The invention concerns a method for producing a security document having an opaque fibrous texture, so as to constitute on the surface of the document at least a highly transparent zone. The invention is characterised in that the method comprises a local treatment of the fibrous texture of the document in said zone, so as to enhance its transparency, and the method comprises the exposure of the locally treated zone to the vibration of a sonotrode at an ultrasonic frequency.</p> |
