(For example, the HP Color LaserJET 8500 series does not include any yellow tracking dots that we can see, but it may still include some kind of forensic marking, since the majority of other Color LaserJET models do. Limitations of this informationĪ 'no' simply means that we couldn't see yellow dots it does not prove that there is no forensic watermarking present. We tried to interpret the information conveyed by these dots as part of our Machine Identification Code Technology Project. This is a list of color laser printer models that do or do not print yellow tracking dots on their output. THIS ALSO INCLUDES THE PRINTERS THAT ARE LISTED HERE AS NOT PRODUCING YELLOW DOTS.įorensic investigations of the source of documents produced with other printing technologies are also possible, but, as far as we know, printers other than color laser and similar technologies do not deliberately encode their serial numbers in their output. THIS IS TRUE WHETHER OR NOT THOSE CODES ARE VISIBLE TO THE EYE AND WHETHER OR NOT THE PRINTER MODELS ARE LISTED HERE. (Added 2017) REMINDER: IT APPEARS LIKELY THAT ALL RECENT COMMERCIAL COLOR LASER PRINTERS PRINT SOME KIND OF FORENSIC TRACKING CODES, NOT NECESSARILY USING YELLOW DOTS. (If any manufacturer wishes to go on record with a statement to the contrary, we'll be happy to publish that here.) Although we still don't know if this is correct, or how subsequent generations of forensic tracking technologies might work, it is probably safest to assume that all modern color laser printers do include some form of tracking information that associates documents with the printer's serial number. (Added 2015) Some of the documents that we previously received through FOIA suggested that all major manufacturers of color laser printers entered a secret agreement with governments to ensure that the output of those printers is forensically traceable.

Laser printer color test