Covert variable information on ID documents and methods of making same

1. A method for manufacturing an identification document, comprising:

providing a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light, and wherein the first color component comprises a thermally diffuseable dye dissolved in a resin;

applying heat to a portion of the first panel so as to form a first variable indicium on a substrate, where the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light; and

wherein the first type of light is one of ultraviolet and infrared light.

2. The method of claim 1 wherein the thermal transfer printing medium further comprises a second panel, the second panel comprising a second color component associated with a second color, the second color component being not visible to the human eye in ambient light; and

being one of infrared and ultraviolet light.

3. The method of claim 2 wherein the second color component comprises a thermally diffuseable dye dissolved in a resin.

4. The method of claim 2 , wherein the first variable indicium appears to have at least a first color when viewed using the first type of light and at least a second color when viewed using the second type of light.

5. The method of claim 1 , wherein the first variable indicium comprises a full color image.

6. The method of claim 1 , wherein the first variable indicium is constructed and arranged so that at least a portion of the first variable indicium is diffused within the substrate and a portion of the first variable indicium is disposed on top of the substrate.

7. An identification document, comprising:

a substrate; and

a first variable indicium printed on the substrate using a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light, wherein the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light; and

wherein the first type of light is one of ultraviolet and infrared light.

8. The identification document of claim 7 , wherein the substrate further comprises a second variable indicium, the second indicium being visible to the human eye in a second type of light; and

wherein the second type of light is one of infrared and ultraviolet light.

9. The identification document of claim 8 , wherein the first type and the second types of light are different.

10. A method for manufacturing an identification document, comprising:

providing a substrate constructed and arranged to receive printing thereon;

printing a first variable indicium on the substrate, where the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light, the first type of light being one of ultraviolet and infrared light

printing a second variable indicium on the substrate, the second variable indicium being visible when viewed using ambient light.

11. The method of claim 10 , wherein the first variable indicium is at least partially superimposed over the second variable indicium.

12. A method for manufacturing an identification document comprising:

providing a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light;

applying heat to a portion of the first panel so as to form a first variable indicium on a substrate, where the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light, and wherein the first variable indicium is a least partially superimposed over the second variable indicium;

wherein the thermal transfer printing medium further comprises a second thermal transfer panel, the second thermal transfer panel comprising a colorant visible to the human eye in a second type of light, the second type of light being different than the first type of light, and wherein the second thermal transfer panel further comprises a covert colorant that is invisible to the human eye in ambient light;

printing a second variable indicium on the substrate using the second thermal transfer panel, the second variable indicium being visible when viewed using the second type of light, wherein the second variable indicium is viewable in both ambient light and in the first type of light; and

wherein the first and the second types of light are one of ultraviolet and infrared light.

13. An identification document, comprising:

a substrate;

a first variable indicium printed on the substrate using a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light, wherein the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light;

wherein the substrate further comprises a second variable indicium, the second variable indicium being visible to the human eye in a second type of light;

wherein the first variable indicium conveys substantially the same information as the second variable indicium; and

wherein the first and the second types of light are one of ultraviolet and infrared light.

14. An identification document comprising:

a substrate; and

a first variable indicium printed to the substrate using a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light, wherein the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light;

wherein the substrate further comprises a second variable indicium, the second variable indicium being visible to the human eye in a second type of light and wherein the first variable indicium overlays at least a portion of the second variable indicium; and

wherein the first and the second types of light are one of ultraviolet and infrared light.

15. identification document, comprising:

a substrate; and

a first variable indicium printed to the substrate using a thermal transfer printing medium comprising a first panel, the first panel comprising a color component that is not visible to the human eye in ambient light but is visible to the human eye when viewed using a first type of light wherein the first variable indicium is not visible to the human eye in ambient light but is visible to the human eye when viewed using the first type of light;

wherein the substrate further comprises a second variable indicium, the second variable indicium being visible to the human eye in a second type of light;

wherein the first variable indiciurn is printed in registration with the second variable indicium; and

wherein the first type of light is one of ultraviolet and infrared light and the second type of light is one of ultraviolet and infrared and ambient light.