Yellow Dots of Mystery: Is Your Printer Spying on You?


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.

In this instructable, we'll describe three different ways to see the tracking dots your printer produces: with a blue light, with a microscope, or with a scanner. If you don't have the necessary equipment for a particular step, go on to the next one.

For further information, or to share your findings, please visit us at

Want to help? Download test sheets at
Remove these adsRemove these ads by Signing Up

Step 1: Print a page with text/graphics

Picture of Print a page with text/graphics

Print out a page from a color laser printer. The page should use color and have some text or graphics on it. You can find a list of printers that we know print tracking dots at our website.

As you're looking for the dots, keep in mind that they're printed in a regularly repeating pattern across the entire page (not just in the corner of the page), and will be intermixed with other printed data.

1-40 of 200Next »

what's with all the bots here? their accounts advertise insurance and cruise websites. they are the ones with single word comments and comment the same stuff on other 'ibles.

yieldlymph2 months ago


Colonel Hogan2 months ago

this is like the NSA spying on our phone conversations

paverphalange6 months ago

his is wrong in so many ways and quite disturbing as well come to think of it...

motherprune7 months ago

Thats sweet

cobbledbeard7 months ago

his is wrong in so many ways and quite disturbing as well come to think of it...

mousepaper7 months ago

Its fabulous :)

Its nice

amazedgreen7 months ago

Thats remarkable

fastbobble7 months ago

Thats astounding

gorgeddamp7 months ago

Thats astounding

clearedeager7 months ago

Its extraordinary

illrings8 months ago

Thats cold

airbugger8 months ago


Its extraordinary

headlymph8 months ago


tealrink8 months ago


grousebandit8 months ago

Thats magnificent...

harechubby9 months ago


jiffymanager9 months ago


calmlunch9 months ago


spewlocks9 months ago


clapfilk9 months ago



spongeraffle9 months ago

Its nice

workexaminer10 months ago

Thats hip

bearblue11 months ago


bearblue11 months ago


gazumpglue11 months ago

Very weird and strange.

Very weird and strange.
BunnyRoger1 year ago
Scary facts.
This is wrong in so many ways and quite disturbing as well come to think of it...
MAApleton1 year ago
I find this just a tiny bit silly, or it it just me?
jillef1 year ago
What about scanned documents? If a document if scanned from any scanner and then saved as a jpeg and sent as an email where the IP cannot be tracked is there any data that can be found then on those jpegs?
Thank you so much :) You made my day !!
heckstallw1 year ago
Its usful
rickafost1 year ago
sensational and informative
1-40 of 200Next »