The dots’ minuscule size, covering less than one-thousandth of the page, along with their color combination of yellow on white, makes them invisible to the naked eye, Crean says. One way to determine if your color laser is applying this tracking process is to shine a blue LED light–say, from a keychain laser flashlight–on your page and use a magnifier.
The best website up about the tracking dots is over at the Electronic Frontier Foundation. The EFF has sent in a FOIA request for information on the program. So far, they say,
“[the] documents we’ve begun to receive in response to our FOIA requests suggest that the government may have convinced all printer manufacturers to put some kind of tracking mechanism in every color laser printer.”
The EFF has discovered the key to the tracking dot code, as shown in the picture here. They reveal the printer serial number and the exact date — down to the minute — of when the document was printed.
Table of printers
Imagine that every time you print a document, it automatically includes a secret code that could be used to identify the printer — and, potentially, the person who used it. Sounds like something from a spy movie, right?
Unfortunately, the scenario isn’t fictional. Most color laser printers and color copiers are designed to print invisible tracking codes across every single printed page of their output. These codes reveal which machine produced a document and, in some cases, when the document was printed or copied.
Because of their limited contrast with the background, the forensic dots are not usually visible to the naked eye under white light. They can be made visible by magnification (using a magnifying glass or microscope), or by illuminating the page with blue instead of white light. Pure blue light causes the yellow dots to appear black. It can be helpful to use magnification together with illumination under blue light, although most individuals with good vision will be able to see the dots distinctly using either technique by itself.
Manufacturer | Model | Dots? | Comments |
---|---|---|---|
Brother | |||
HL-2700CN | yes | volunteer test | |
HL-4200CN | yes | EFF test | |
Canon | |||
CLC 1000 | yes | EFF test |
|
CLC 2400 | yes | EFF test |
|
CLC 3002 | yes | EFF test |
|
CLC 4000 | yes | EFF test |
|
CLC 5000+ | yes | EFF test | |
CLC-iR 3200-C1 | yes | EFF test | |
Color imageRUNNER C2570 | yes | EFF test | |
Color imageRUNNER C3100CN | yes | EFF test | |
Color imageRUNNER C3200 | yes | EFF test | |
Color imageRUNNER C3200N | yes | EFF test | |
Color imageRUNNER C3220 | yes | EFF test | |
Color Laser Copier 1150 | yes | EFF test | |
Imageclass MF8170C | yes | EFF test | |
LBP 2410 | unclear | faint dots; could be artifacts | |
Dell | |||
3000CN | yes | EFF test |
|
3100CN | yes | EFF test |
|
5100CN | yes | EFF test |
|
Epson | |||
AcuLaser C900 | yes | EFF test | |
AcuLaser C1100 | yes | EFF test | |
AcuLaser C1500 | yes | EFF test | |
AcuLaser C1900 | yes | EFF test | |
AcuLaser C3000 | yes | EFF test | |
AcuLaser C4000 | yes | EFF test | |
Fuji: see Xerox | |||
Hewlett-Packard | |||
Color LaserJET 1550L | yes | EFF test | |
Color LaserJET 1600 | yes | EFF test | |
Color LaserJET 2250LN | no (??) |
EFF test | |
Color LaserJET 2500 | yes | EFF test | |
Color LaserJET 2500L | yes | EFF test | |
Color LaserJET 2500N | yes | EFF test | |
Color LaserJET 2550 | yes | EFF test | |
Color LaserJET 2550L | yes | EFF test | |
Color LaserJET 2550N | yes | EFF test | |
Color LaserJET 2600N | yes | EFF test | |
Color LaserJET 2680 | yes | EFF test | |
Color LaserJET 2700N | yes | volunteer test | |
Color LaserJET 2840 | yes | EFF test | |
Color LaserJET 3500 | yes | EFF test | |
Color LaserJET 3550 | yes | EFF test | |
Color LaserJET 3600DN | yes | EFF test | |
Color LaserJET 3700 | yes | EFF test | |
Color LaserJET 3700DN | yes | EFF test | |
Color LaserJET 3700N | yes | EFF test | |
Color LaserJET 4500 | no | EFF test | |
Color LaserJET 4500DN | no | EFF test | |
Color LaserJET 4500N | no | EFF test | |
Color LaserJET 4550 | no | EFF test | |
Color LaserJET 4550N | no | EFF test | |
Color LaserJET 4600 | yes | EFF test | |
Color LaserJET 4600DN | yes | EFF test | |
Color LaserJET 4600HDN | yes | EFF test | |
Color LaserJET 4600N | yes | EFF test | |
Color LaserJET 4650 | yes | EFF test | |
Color LaserJET 4650DN | yes | EFF test | |
Color LaserJET 4650DTN | yes | EFF test | |
Color LaserJET 4700 | yes | volunteer test | |
Color LaserJET 4700DN | yes | volunteer test | |
Color LaserJET 4700DTN | yes | volunteer test | |
Color LaserJET 5M | no | EFF test | |
Color LaserJET 5100CN | yes | EFF test | |
Color LaserJET 5500 | yes | EFF test | |
Color LaserJET 5500ATN | yes | EFF test | |
Color LaserJET 5500DN | yes | EFF test | |
Color LaserJET 5500HDN | yes | EFF test | |
Color LaserJET 5550 | yes | EFF test | |
Color LaserJET 5550DN | yes | EFF test | |
Color LaserJET 5550DTN | yes | EFF test | |
Color LaserJET 8500 | no | EFF test | |
Color LaserJET 8500DN | no | EFF test | |
Color LaserJET 8550 | no | EFF test | |
Color LaserJET 8550DN | no | EFF test | |
Color LaserJET 8550GN | no | EFF test | |
Color LaserJET 9500 | yes | EFF test | |
Color LaserJET 9500HDN | yes | EFF test | |
Color LaserJET 9500MFP | yes | EFF test | |
IBM | |||
Infoprint Color 1454 | unclear | dithering? | |
Infoprint Color 1464 PS3 | yes | dithering? | |
Konica (Konica/Minolta) |
|||
Bizhub C252 | yes | EFF test | |
Bizhub C350 | yes | EFF test | |
Colorforce 1501 | yes | EFF test | |
Colorforce 8050 | yes | EFF test | |
DialtaColor CF 2001 | unclear | dithering? | |
DialtaColor CF 2002 | unclear | dithering? | |
Ikon CPP500E | yes | EFF test | |
Magicolor 2 Desklaser | no | EFF test | |
Magicolor 2200 DL | yes | EFF test | |
Magicolor 2210 | yes | EFF test | |
Magicolor 2300 DL | yes | EFF test | |
Magicolor 2300 W | yes | EFF test | |
Magicolor 2350 | yes | EFF test | |
Magicolor 2350 EN | yes | EFF test | |
Magicolor 2400 W | yes | EFF test | |
Magicolor 2430 DL | yes | EFF test | |
Magicolor 2450 | yes | EFF test | |
Magicolor 3100 | yes | EFF test | |
Magicolor 3300 | yes | EFF test | |
Magicolor 5450 | yes | EFF test | |
Magicolor 7300 | yes | EFF test | |
Kyocera | |||
C2630D | yes | EFF test | |
FS-C5016N | yes | EFF test | |
FS-C5020N | yes | EFF test | |
FS-C5030N | yes | EFF test | |
FS-C8008 | yes | EFF test |
|
Mita KM-C2230 | yes | EFF test | |
Lanier | |||
LD238C | yes | EFF test |
|
LP125CX/LP126CN | yes | EFF test | |
Lexmark | |||
C510 | yes | EFF test |
|
C720 | unclear | retest | |
C752 | yes | EFF test |
|
C752N | yes | EFF test |
|
C760 | yes | EFF test |
|
C910 | yes | EFF test |
|
C912 | yes | EFF test |
|
Minolta: see Konica |
|||
NRG | |||
DSc38 | yes | EFF test |
|
OkiDATA (Oki) |
|||
C5100 | no | EFF test |
|
C5150 | no | EFF test |
|
C5150N | no | EFF test |
|
C5200 | no | EFF test |
|
C5300 | no | EFF test |
|
C7200 | no | EFF test |
|
C7350 | no | EFF test |
|
C7400 | no | EFF test |
|
C7400N | no | EFF test |
|
C9200 | no | EFF test |
|
C9300 | no | EFF test |
|
C9400 | no | EFF test |
|
MIP C5540 | no | EFF test |
|
OkiLAN 8100E | no | EFF test | |
Panasonic | |||
Workio KXCL-500 | yes | EFF test | |
Ricoh (see also Savin) |
|||
Aficio 1224C | yes | EFF test | |
Aficio 1232C | yes | EFF test | |
Aficio CL 2000 | yes | press report | |
Aficio CL 3000 | yes | EFF test | |
Aficio CL 3000E | yes | EFF test | |
Aficio CL 6010 | yes | EFF test | |
Aficio CL 7000 | yes | EFF test | |
AP 206 | yes | EFF test |
|
Infotec/Danka ISC 2838 | yes | EFF test | |
Samsung | |||
CLP-500 | no | EFF test |
|
CLP-510 | no | EFF test |
|
CLP-550 | no | EFF test |
|
CLP-550N | no | EFF test |
|
Savin | |||
C3210 | yes | EFF test |
|
CLP35 | yes | EFF test |
|
Tektronix: see Xerox |
|||
Toshiba | |||
eStudio 210c | yes | mfr. statement | |
eStudio 211c | yes | mfr. statement | |
eStudio 310c | yes | mfr. statement | |
eStudio 311c | yes | mfr. statement | |
eStudio 2100c | yes | mfr. statement | |
eStudio 3100c | yes | mfr. statement | |
eStudio 3511 | yes | EFF test | |
FC15 | yes | mfr. statement | |
FC15i | yes | mfr. statement | |
FC22 | yes | mfr. statement | |
FC22i | yes | mfr. statement | |
FC25P | yes | mfr. statement | |
FC25Pi | yes | mfr. statement | |
FC70 | yes | mfr. statement | |
Xerox (Tektronix) |
|||
DocuColor 12 | yes | EFF test | |
DocuColor 40 | yes | EFF test | |
DocuColor 1521 | yes | EFF test | |
DocuColor 1632 | yes | EFF test | |
DocuColor 2000 | yes | mfr. statement | |
DocuColor 2045 | yes | EFF test | |
DocuColor 2240 | yes | EFF test | |
DocuColor 3535 | yes | EFF test | |
DocuColor 5252 | yes | EFF test/mfr. statement | |
DocuColor 6060 | yes | EFF test/mfr. statement | |
Phaser 560 | no | EFF test | |
Phaser 740 | no | EFF test | |
Phaser 750 (Z750V) | no | EFF test | |
Phaser 750P | no | EFF test | |
Phaser 790 | yes | EFF test | |
Phaser 850DP | no | EFF test | |
Phaser 860DP | no | EFF test | |
Phaser 1235 | no | EFF test | |
Phaser 6100 | no | EFF test | |
Phaser 6200 | no | EFF test | |
Phaser 6200DP | no | EFF test | |
Phaser 6250DP | no | EFF test | |
Phaser 6350DP | no | EFF test | |
Phaser 7300DN | no | EFF test | |
Phaser 7300DT | no | EFF test | |
Phaser 7700 | no | EFF test | |
Phaser 7750DN | no | EFF test | |
Phaser 8200DP | no | EFF test | |
Phaser 8200DX | no | EFF test | |
Phaser 8400 | no | dithering? | |
Phaser 8400B | unclear | dithering? | |
Phaser 8400DP | unclear | dithering? | |
Phaser 8400DX | unclear | dithering? | |
Phaser 8400N | unclear | dithering? | |
Phaser 8440DP | unclear | dithering? | |
Phaser 8550 | no | EFF test | |
Phaser 8550DP | no | EFF test | |
Phaser 8560MFP/D | no | EFF test | |
WorkCentre M24 | yes | EFF test | |
WorkCentre Pro (all models) |
yes | mfr. statement |