DE1646225

1,200,021. Preventing fraud; identification cards. ADDRESSOGRAPH - MULTIGRAPH CORP. 12 Jan., 1968 [12 Jan., 1967], No. 1958/68. Heading B6A. [Also in Division B8] A credit card 12 of thermoplastic material is provided with a signature area 20 to which a thin thermoplastic signature strip is heat bonded, the signature strip being receptive to ink and bearing a distinctive non-reproducible pattern 30 on its surface, whereby attempted removal of a portion of the signature causes defacing of a portion of the pattern. The area beneath the signature strip may be provided with indicia 28 voiding the device. The distinctive pattern 30 may be formed on a thin protective film of thermoplastic material bonded to the signature strip. The signature strip is applied to the card base by a method comprising providing a carrier strip (34), Fig. 4 (not shown), for the signature strip, applying the assembly of the carrier strip and signature strip to the card base by heat and pressure, and removing the carrier strip. The pattern 30 may be printed on the carrier strip, or formed as an engraved pattern on the die for applying pressure.