Tonernews.com, November 11, 2005. USA
How it works:
http://www.eff.org/Privacy/printers/docucolor/
Automated decoder at http://www.eff.org/Privacy/printers/docucolor/#program
This is an image of one repetition of the dot grid from the same Xerox DocuColor 12 page, magnified 10x and photographed by the QX5 microscope under illumination from a Photon blue LED flashlight. Note that the increased contrast under blue light allows us to see the entire dot pattern clearly.