The only makers that did not have a positive result in the EFF tests were Oki and Samsung.

The printer makers that had tracking patterns on some or all of the tested printers were: The Electronic Frontier Foundation did tests on many printers and found that they all had a tracking pattern. If you have a color printer – ink or laser – then your printed pages will have the secret dots added. Which printers have the tracking dots?Īll the major printer makers have added a secret tracking pattern. The pattern is faint but even a scan or photo of a printed page was enough for the FBI experts to detect it. Law enforcement or anyone else who knows how to decode the pattern can tell when a page was printed and the exact printer used. The pattern indicates the printer type (make, model), exact printer used (serial number) plus date and time printed. Page from HP Color Laserjet 3700 normal (left) and under blue light (right) Source: Florian Heise, & Wikipedia. The pattern is repeated across the entire page.

It’s a very faint pattern of yellow dots added to every printed page on most, if not all, color printers.

Each page told the FBI when the page was printed and which specific printer was used to make it.īecause Office Watch readers print almost every day, we’ve combed the available knowledge about this secret US government program to find out what’s known and what’s unknown (Rumsfeld style). One piece of evidence against Reality Winner was the secret code on the pages she allegedly leaked. It’s just one result of last week’s NSA leak and later arrest. Most color printers have a secret tracking or forensic code added to every page that lets governments and others know when and where the page was printed.

Laser printer color test