| abstract |
A multi-layered engraved identification card includes a base layer having a first color and a color-changeable layer initially having a second color which is changeable to a third color contrasting with the first color upon exposure to radiant energy preferably having a wavelength of from 3,500 to 5,000 Angstroms, for a specified period of time. The color-changeable layer is initially prepared as a solution of a resin, a plasticizer, a radiant energy-sensitive coloring agent for causing the color change, and a solvent in which both the base and the resin of the solution are soluble. Alternatively, the solution may further include a cross-linkable plasticizer with a peroxide to cause the resin of the solution and the plastic of the base to be cross-linked and hence bonded permanently to the base. The engraving may be done after the color-changeable layer is formed on the base, or alternatively, the base may be first engraved and the color-changeable solution applied to the non-engraved surface regions or applied to fill the engraved depressions. |