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secret yellow dots in my laser printouts |
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Written by admin
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Oct 25, 2008 at 09:11 PM |
The yellow dot pattern secretly printed onto every one of my documents. Viewed under blue light this dot pattern from an HP colour laser jet appears black. Apparently, each pattern is unique to the machine and encodes it's model and serial number.
I've illuminated this printout using the overpowering blue LED of an Aldi Tevion mini amplified speaker system.
More secret dot info here at the Electronic Frontier Foundation; www.eff.org/issues/printers
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Last Updated ( Oct 25, 2008 at 09:14 PM )
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