| 摘要 |
A method of manufacturing a security card blank (7) is described. The method comprises a) assembling together a plurality of layers (1, 5), an internal layer (5) comprising a radiation absorbent metallic layer; and b) securing the layers (1-5) together such that the metallic layer (5) is secured by a controlled amount to the adjacent layers (1, 4) to allow the metallic layer to be imaged by a high intensity radiation beam. A security card (9) may be manufactured from the blank (7) by c) exposing the metallic layer (5) in the security card blank to radiation whereby the metallic layer is modified to produce an image (8) in the metallic layer, the arrangement being such that in the finished card at least part of the imaged metallic layer is detectable from outside the card. |
