[kiryandil]

The matrix decodes the placement of the markings and reveals the precise identity of the printer by serial number along with the exact date and time the document was printed

I was Printer Guy for my IT department at a university back in the day.

Yeppers.

[Not_Who_U_Think]

This is why making your own $100 bills on a color printer is such a bad idea.

[RightOnTheBorder]

IIRC this is how they caught that chick Reality Winner printing out top secret docs.