Watermark printed on matching color media forming metameric pair
A marking color of a marking material (e.g., ink, toner, etc.) within a printer has a marking spectral reflectance property. Print media that has a media color approximately matching the marking color, but a different media spectral reflectance property, is identified (to form a geometric metameric pair). Differently colored calibration patches of the marking material are printed on a test sheet of the print media. A calibration patch, in which the printed color of the marking material most closely visually matches the media color, is used to identify a revised marking color. A watermark is printed on the print media using the revised marking color. The difference between the marking spectral reflectance property and the media spectral reflectance property causes the watermark to be visibly observable on the print media from one angle but prevents the watermark from being visibly observable from a different angle.
1. A method comprising:
automatically identifying a marking color of a marking material within a printer using a processor of the printer, wherein the marking material has a marking spectral reflectance property;
automatically identifying a print media having a media color matching the marking color and having a media spectral reflectance property that has a different amount of spectral reflectance from the marking spectral reflectance property using the processor;
automatically printing differently colored calibration patches of the marking material combined with different colorants on a test sheet of the print media using a printing engine of the printer;
automatically identifying, as a matching calibration patch, one of the calibration patches printed on the test sheet in which a printed color of the marking material most closely visually matches the media color using an optical scanner of the printer; and
automatically identifying a revised marking color used to print the matching calibration patch using the processor; and
automatically printing a watermark on the print media by applying the marking material to the print media using the printing engine, wherein the printing of the watermark is performed using the revised marking color.
2. The method according to claim 1 , wherein the marking color and the media color comprise a geometric metameric pair and are matching colors with different spectral reflectance properties.
3. The method according to claim 1 , wherein the marking spectral reflectance property is different in spectral reflectance from the media spectral reflectance property by at least twice as much spectral reflectance.
4. The method according to claim 1 , wherein the marking material comprises a permanent color.
5. The method according to claim 1 , wherein a difference between the marking spectral reflectance property and the media spectral reflectance property causes the watermark to be visibly observable on the print media from a first angle and prevents the watermark from being visibly observable on the print media from a second angle that is different from the first angle.
6. The method according to claim 1 , wherein the printing of the watermark is performed by applying a single layer of the marking material to the print media.
7. A system comprising:
a printing device comprising:
a storage component specifically configured to maintain a marking material; and
a media supply, wherein the printing device is adapted to print differently colored calibration patches of the marking material combined with different colorants on a test sheet of the print media;
an optical scanner in communication with the printing device, wherein the optical scanner is configured to scan the differently colored calibration patches on the test sheet; and
a processor in communication with the optical scanner and the printing device,
wherein the processor is configured to identify a marking color of the marking material within a storage compartment,
wherein the marking material has a marking spectral reflectance property,
wherein the processor is configured to identify a print media in the media supply having a media color matching the marking color and having a media spectral reflectance property that has a different amount of spectral reflectance from the marking spectral reflectance property,
wherein the processor is configured to identify from the scan performed by the optical scanner, as a matching calibration patch, one of the calibration patches printed on the test sheet in which a printed color of the marking material most closely visually matches the media color,
wherein the processor is configured to identify a revised marking color used to print the matching calibration patch, and
wherein the printing device is configured to print a watermark on the print media using the revised marking color.
8. The system according to claim 7 , wherein the marking color and the media color comprise a geometric metameric pair and are matching colors with different spectral reflectance properties.
9. The system according to claim 7 , wherein the marking spectral reflectance property is different in spectral reflectance from the media spectral reflectance property by at least twice as much spectral reflectance.
10. The system according to claim 7 , wherein the marking material comprises a permanent color and the revised marking color comprises a mixture of multiple permanent colors.
11. The system according to claim 7 , wherein a difference between the marking spectral reflectance property and the media spectral reflectance property causes the watermark to be visibly observable on the print media from a first angle and prevents the watermark from being visibly observable on the print media from a second angle that is different from the first angle.
12. The system according to claim 7 , wherein the watermark is printed by applying a single layer of the marking material to the print media.
13. A system comprising:
a printing device, wherein the printing device is adapted to print differently colored calibration patches of marking material combined with different colorants on a test sheet of print media;
an optical scanner in communication with the printing device, wherein the optical scanner is configured to scan the differently colored calibration patches on the test sheet; and
a processor in communication with the optical scanner and the printing device,
wherein the processor is configured to identify a marking color of the marking material within a storage compartment,
wherein the marking material has a marking spectral reflectance property,
wherein the processor is configured to identify a print media having a media color matching the marking color and having a media spectral reflectance property that has a different amount of spectral reflectance from the marking spectral reflectance property,
wherein the processor is configured to identify from the scan performed by the optical scanner, as a matching calibration patch, one of the calibration patches printed on the test sheet in which a printed color of the marking material most closely visually matches the media color,
wherein the processor is configured to identify a revised marking color used to print the matching calibration patch, and
wherein the printing device is configured to print a watermark on the print media using the revised marking color.
14. The system according to claim 13 , wherein the marking color and the media color comprise a geometric metameric pair and are matching colors with different spectral reflectance properties.
15. The system according to claim 13 , wherein the marking spectral reflectance property is different in spectral reflectance from the media spectral reflectance property by at least twice as much spectral reflectance.
16. The system according to claim 13 , wherein the marking material comprises a permanent color and the revised marking color comprises a mixture of multiple permanent colors.
17. The system according to claim 13 , wherein a difference between the marking spectral reflectance property and the media spectral reflectance property causes the watermark to be visibly observable on the print media from a first angle and prevents the watermark from being visibly observable on the print media from a second angle that is different from the first angle.
18. The system according to claim 13 , wherein the watermark is printed by applying a single layer of the marking material to the print media.