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
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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.

yieldlymph1 month ago


this is like the NSA spying on our phone conversations

paverphalange5 months ago

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

motherprune6 months ago

Thats sweet

cobbledbeard6 months ago

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

mousepaper6 months ago

Its fabulous :)

Its nice

amazedgreen6 months ago

Thats remarkable

fastbobble6 months ago

Thats astounding

gorgeddamp6 months ago

Thats astounding

clearedeager6 months ago

Its extraordinary

illrings6 months ago

Thats cold

airbugger7 months ago


Its extraordinary

headlymph7 months ago


tealrink7 months ago


grousebandit7 months ago

Thats magnificent...

harechubby7 months ago


jiffymanager7 months ago


calmlunch8 months ago


spewlocks8 months ago


clapfilk8 months ago



spongeraffle8 months ago

Its nice

workexaminer8 months ago

Thats hip

bearblue9 months ago


bearblue9 months ago


gazumpglue10 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
itsme1235 years ago
why could not you just print a blank page many times thru different printers ( or print in white something like a period). running it thru top first , then bottom first then thru other printers, it would be hard to tell which printer made which mark making it hard to tell exactly where each mark came from
vov35 itsme1233 years ago
It's impractical to do so on a regular basis to help prevent being spied upon, but yes, this would cause problems with their system. Congratulations, now the system is only useful for invading our privacy and not preventing fraud. :D
"It's outrageous that manufacturers make secret deals to compromise our privacy." What privacy? How many times do you send a letter to some one and you do not want them to know who sent it? This is not any different than your IP address being included in an email or saved at a website.
when you print something you expect it to be anonymous unless you intentionally signed it for love letter (do you really want it to be anonymous ?) you probably just print and its anonymous. for some other stuff you may want to use a generic font / shred the text with babelfish / handle the page with gloves. you sure dont want the dots there
The dot's don't identify the person, right? Just the printer. Then this has nothing to do with privacy. The dots will only tell someone that a XXXprinter printed it, not Bob Smith printed it.
scenario 1 your boss asked you to print some stuff for him with deadline. deadline passed and you did not do that. boss calls and asks whyits not ready. you tell him you sent and thats the mail service fault (and not yours). you sit to print it and remember to write there the date of 2 days ago (to make the show perfect) boss recieves the mail. he is freaked off how late the docs arrived and shares his rage with a friend. his friend suggests him to check the true date encoded in the dots and decode that using the calculator in the EFF site scenario 2 you are a journalist who uses the computer for his professional stuff as well as his personal stuff. he prints a doccument that he wants to make confidential so that no one can get on him if the document falls in the wrong hands. the document does a month ago his daughter married an he printed the invitation letters on the same printer. one of those letters is enough to link him to the confidential doc via the printer serial number the dots contain information that you did not intend to include in the document you print and you are likely to be unaware of its existence. this is a privacy issue. no need in your name it may be very complicated to find by incident a titled document printed on the same printer - so it does not look that severe. possibilities become huge when dots meet other info that can be esily crossed with them - like where was batch of printers of model X and manufacture date Y sold - probably available from the manufacturer lets wait for the EFF guy to explain more
Cereleste, you are correct, the information is just Lexmark - serial number xxxx-xxxxx-xxxxxx and perhaps the date and time. This is not printing out your name, address, and contact information. 11010010110: Both Scenarios are possible, but not really probable. Unless that Boss makes it a policy to look at the dots on each page, then he probably would not even think about it. If someone is using a printer for both "questionable" business practices and personal use, he deserves to be caught. Base line point is this: If you are printing something out that you do not want to be linked to in any way what so ever, make sure you have an older printer that does not support the dot printing.
Post Script: This is nothing new. Forensic Detectives used to be able to tell what typewriter was used to create a letter based on the pits in the letters as they stamped into the ribbon and paper. Some companies would even put these pits into their letters on purpose so that it was a form of signature that their typewriter was used.
You do realize there are other ways to tell where a document came from... Forensic scientists and the FBI don't need fancy dots to tell them where a document came from. And if every model has a different method of placing dots, it would take more money and time to develop a database of different methods and then cross check the dots with the database. I don't believe it's worth it. And i guarantee I'll get a scathing reply about "the man" and how "big-brother" is watching, but i still believe that this is the printer manufacturers decision and not the government violating your freedom of speech.
But such a database would connect a document to a model of printer, not to an individual printer, as the coded dots do. Nothing to do with big brother watching or free speech. The USA darn nearly descended into McCarthyism, with no respect for the bill of rights, post 9/11. No need to give the government more tools to harass anyone that doesn't tow the nationalists line.
vov35 static3 years ago
most high value electronics have a unique serial number. they can identify the specific printer that this came from.
The government doesn't harass those that don't "tow
not  true the fbi created the method... i fix copiers.  no color copier is allowed to be sold in the usa without this dot pattern encoded in the image it is created in the print engine not from the image process even when the machine is internaly calibrating itself these dots are formed and visable  on the transfer belt  the only information encoded  in the dots is model numbers and time and date that way if a faudulent document is found it can be traced back to the source day the fbi showed up and took an entire machine as evidence when some funny money showed up...BTW most high end color copiers can detect money being prited on them and will actually code to the point where your local rep cant fix it and a rep from the manufacturer has to come in and reset it  ...that how deep the rabbit hole goes my friend  for the manufacture i represent there are only 4 people in the usa that can reset that code
Then why ask the printer companies to institute the yellow dots, if they don't need them? And if they asked them to include this technology, then don't you think they maintain a comprehensive database of what the dots mean? It's not like Xerox/XP/Canon etc. has a vested interest in what you print.
i think the effort it would take to maintain a database of yellow dot patterns outweighs the benefit. To answer your question, no i don't think the government maintains a database of yellow dot patterns, and Xerox, HP, Canon, Brother DO have a vested interest in what you print, or rather how you print.
You are correct, this is not something that the government has in created, it is only a digital signature of the printer. Now if someone were to say print off a threating letter and send it to someone, then this could be used to help track the person in question down. But just by looking at the dots on the page would not be all that it takes.
my point exactly.
Comparing apples to oranges. The detectives have to have both the document and typewriter in hand to connect the document to a typewriter, and the typewriter to an user. Same goes for using old school methods used to match a document to a printer. Now only the document is the only thing needed to connect it to a specific printer.
out of curiosity what does your name say in binary?
ash? Then why does my binary translator says you are Ò ?
11010010110 --> 10100101 --> A5 (hex) --> A5h --> Ash
Nice! Why do you trim the "1" and "10" though? Signal start/end?
I know of at one count of the operator being identified and convicted by comparing the operator log with the time stamp in the code. I serviced one particular color printer that included firmware to recognize currency. We were warned, sternly, during training that we should NOT attempt it. The instructors stated that they did not know how the firmware worked or how it affected the printer. Since it was a network printer it had the capability of reporting such attempts.

I typed that link freehand, but it probably works
Not only that, even my scanner (canonscan lide 90) can't scan currency (tried it Euro). What is the logic in that??? So I can't send pictures of money? I should return it to the shop.
wow ! this story with firmware just shows how the _government_ is paranoid what make and model is that printer ?
Xerox - I worked for them 33 years. The technology is used in mostly color and all models have something similar. The quality was so good that copies would be accepted by scanners. Something had to be done to prevent counterfeit.
Yes, So smash your printer with a hammer, and print at the library. Except it's still an invasion of your privacy.
However if you send in your warranty card, your privacy would be compromised. Your choices. Rick that the product you buy isn't a lemon, and don't send in the card. Protect you pocket book, by risking your security. Today merchandise can be trace from factory to retailer. Not a stretch to imagine the trace from retailer to purchaser. I fail to trust that every bar coded item I purchase is not link to my checking and/or CC accounts. Paranoia? Perhaps, how can we know for sure?
bar codes are not an issue - they are the same on all stuff of the same type you'd better go google on RFID :) many new printers come now with online registration feature in the setup wizard. im sure this registration includes serial # of the printer and some data from the computer we have one such printer / scanner combo from HP and the thing is quite annoying (with options only 'now' and 'later' and cannot be disabled. it gets back to startup when you use the scanner)
So, invading your privacy is ok, since you've go nothing to hide, right? I'll be sure to hack instructables to get every thing I need to know about you to eliminate your intellectual life, get you locked illegally in a government facilty, And have your family and friends searched and bugged. Still Sound like a good Idea?
It's very different actually. Just because we are all spied on while surfing the Internet in the name of security, does not mean that should spread to any other area's of our lives. It is outrageous.
Grimmiger4 years ago
I just love how so many people are getting paranoid about the government watching everything we do and print!
It is not for that.
It is mostly used with services such as law enforcement to be able to identify if a certain note or letter was printed from a certain suspects printer. Also it allows other agencies to determine if it is actually from where the letter says it is from.
Think of it as more of a personalized watermark.
Please do not reply to this comment if all you have to say is the government are out to get us.
vov35 Grimmiger3 years ago
Law enforcement isn't the government or anything.
the government are out to get us
nate1216 years ago
this is creepy however these were made to stop store cleaks can easialy cheak to see if fake. and kids do this alot they print off a few dollars and spend em at the mini mart.
Yes, yes. Many the time has been when I've seen kiddies at the minimart buying skittles and beer with fake money. WTF, dude? You can't just pull this stuff out of your arse.
well, now, by your own admission..... maybe you can ;) lol
yea, cause I'm sure that a clerk who isn't able to identify a fake by the texture of the paper (or by the hundreds of other techniques used by mint to show that money is authentic) would DEFINITELY know how to look for little dots to see if it was made on a color printer. The dots are not intended to stop counterfitters, they are more likely intended to track down people who write bomb threats, ranson notes, etc. Those may be good things, but it's still an invasion of privacy.
Yea, that seems more likely, to track down printed threats of some sort.
Right in that paper money isn't printed on paper, the texture will be the first tip off something is hinky. No doubt there are those that may go through the process to use a paper that's similar to the feel of legal money. But only counterfeit large bills would make that worth the effort. Large bills get closer scrutiny by a clerk, so the chance of getting caught is greater.
hmmmmm your right however some peopl are pretty stupid.
seems logical ...and was my first thought..but the dots may not fit on a bill and only partially...but i dont know how far apart the dots are ..out of curiosity i am going to look into it more
Why is that one guy wearing a lab coat and safty goggles? Is printing really that dangorous? What a joke!!
beehard444 years ago
what if you have black ink?
RN13584 years ago
 I have been servicing copiers and printers for over 30 years (unfortunately). The yellow dots you are talking about are there to prevent counterfitting, not so much for currency, but for Stock certificates, Bonds, etc. I have been told by several manufacturer's reps that the yellow dots are required by the government, but I have not been able to verify that as fact. As for the comment that "your printer is spying on you", Canon, Xerox, Minolta, etc. couldn't care less what you copy...they just want to sell more printers, copiers and supplies! Most newer color copiers also will detect if you try to copy currency, and prevent it from printing out. One model I use to service would generate an error code that had to be reset by the tech if you tried to copy currency; another model would display a warning the first 2 times you tried to copy currency, and on the third attempt, the machine would be disabled, and would require the replacement of a very expensive main pcb to fix the machine. And, of course "nobody here tried to copy money" was the first thing the customer would say!
djr6789 RN13584 years ago
i tried making giant a4 sized £10 notes and my printer stopped working :O and now i know why :O
zomfibame6 years ago
Just a very simple, basic question for you guys; the identification dots printed on home printers..... are they all yellow, in every brand of printer? because if that is the case then... why can't one just adjust the yellow ink 100% down in an expensive printer, and in a cheap one where you can not adjust the percentage of each ink color.... just remove the yellow ink container. If a person wanted to make political publications, I'm thinking that the lack of yellow ink would become a political statement in and of itself; wouldn't it? If the publication had only red, purple, blue, and black, but NO yellow, and as a result, no green.... then that itself would be a political statement. so, like I said, why not just "turn off" the yellow ink? ohhhh, and also, Is there anything at all that I own that the government can't track? hummm, I wonder if they can track my toilet-paper too?
i think that if the printer "decides" to add the dots without your order.. even if you set the yellow settings to 0%, it would still print the dots, even with your specific order.. it would be best just to remove the yellow ink container.. in my hp its not possible to do, since the yellow is together with the magenta and cyan..
A typical color laser printer will not print with one of the cartridges missing. Empty, yes, missing, no.
just replace it woith a different colored empty cartridge!
That would be the same as it being missing, color laser printers can identify whether the cartridge installed is t he right color and won't print if the correct color cartridge is not in every slot. Older models might still print, but most color lasers have been able to identify the cartridge for several years/generations. I checked a website to see if mine was known to do the yellow dots and it wasn't listed because it was too new, but the 2 or 3 prior models from years past that it is based upon are on the list.
Icalasari ac-dc4 years ago
Best solution would be to print using a yellow sheet of paper
Actually, it would be best to just melt shut the opening on an almost empty cartridge; now days, most colored inks come in one cartridge that has the three base colors in it.
Actually, this topic is about color LASER printers and copiers, there is no opening to melt shut, and on many color inkjets the print head is not part of the cartridge anymore so you'd be destroying a part you need to reuse.

The best solution is don't be doing anything that would get your government curious as to who printed something, remembering it means nothing for them to have the dots, they'd also already have to be investigating you to compare YOUR printer to the dots.  The dots themselves may tell them what make/model of printer printed something but not who owns it till them match it up.

Obviously only matching up you as the owner of a particular printer is not conclusive evidence by itself since other people own the same printer, but nevertheless if you're paranoid about being traced back to something you print, the best solution is don't print it at all - or if you must, not on your own printer.
Nyxius ac-dc4 years ago
If they have your serial number from something you printed, then all they have to do is check with to the company that manufactured the printer .  Most people have to register there printer to activate the warranty, and if you've registered then you're traceable.
ac-dc Nyxius4 years ago
That's silly. I've been in the tech business for 20 years and have never "registered" a printer, laws in the US do not allow a warranty to be less than stated on the label if you merely didn't register it.

"Registering" a product is mostly about submitting your email address for spam.

Under NO circumstances is a warranty ever subject to registering it when it was advertised at the time of sale.  Never, ever, this is clear contract law, it would have to be specified as such which no consumer would agree to.

Well, I mean the port that allows the ink out of the cartridge. I also said "nearly empty". If you did it to just that part, or stopped the ink from coming out some other way, it would be OK.
I suspect you need to learn a bit more about laser printers and consider the context.

Remember for one, it's a color laser printer expressly because you want to be able to print color, nobody wants to swap cartridges around unnecessarily, nor damage one by trying to block it, and some printers won't even print with empty cartridges in them (actually most won't).

You could easily damage the printer, or a cartridge worth over $100.  You almost certainly would trying to prevent toner from coming out, and most printers these days are smart enough, optical sensors for print quality and calibration purposes, that it wouldn't even print until you corrected the fault condition.

The real question is why?  Why bother? It is not some challenge you need to try to do, it is a relatively pointless to even try because if someone is up to something that might get them into trouble, it is no hard thing to simply print on a printer that isn't traceable to them, or after printing such an ultra-secret and dangerous page simply wipe down the printer to get rid of fingerprints and throw it away in a trash bin somewhere.

It's a bit like wearing a tin-foil hat, people are not needing to be paranoid, not needing to do anything about it, just a bit of a news item that it was doing that when most people didn't realize it.

Most people don't realize scanner drivers have code in them to detect US currency either, and there's nothing to be concerned about unless someone is up to no good and gets caught.
ac-dc Icalasari4 years ago
You really think the government scanners set up to detect these dots couldn't see toner on a page that's the same color?

I'd bet I could even see it with naked eyes, because today's typical color toner is glossy (high wax content).

Plus, it occurs at a regular interval (spacing per set of dots), the whole point of them is to provide a way for them to be detected/identified.
Icalasari ac-dc4 years ago
Glossy paper? If you can't get a hold of that, then find out the exact colour that the dots are (may take awhile), and then print all of you paper solid yellow, using that exact shade, before using it
ac-dc Icalasari4 years ago
You seem to be overlooking that the ultimate goal is not to foil the "man", it's just to continue using a printer in a cost effective manner.  Who wants yellow paper?

What is the point of a laser printer on  yellow paper?  You do realize a laser printer depends on a white background as the mix for the colors right?  Light blue isn't light blue with yellow paper, it's green.  Gray isn't gray, it's yellow-gray.  Totally defeats the purpose of having a color laser printer.

Also, same exact shade of yellow, on glossy paper, it wouldn't matter.  It still won't have the same reflectivity, toner covers up the paper fiber texture present when it's dyed fibers (to make colored paper), and a simple chemical would react with the paper but not the plasticized and wax toner so no matter what color the paper started, no matter all the other what-ifs, it's still so easy to reveal the dots that any layman with a high school chemistry class under their belt could figure out a way, let alone the government who has full specs on the issues and sophisticated equipment set up for this very thing.
Also no red, as red is made from magenta and, you guessed it, yellow :P
Pulling out the yellow ink may work but you should probably test by yourself on the software adjustment.
mortal1016 years ago
I have no color ink and I bought my printer at a swap meet 3 years ago. They could never track anything to me if they wanted.
Correction: They could never track you via your printer
If you were a suspect, they could find your printer.
typhonx6 years ago
Cereleste: Actually, if the printer encodes it's own ID number, it is VERY easy to find out that "printer X" belongs to "Bob Smith". Every manufacturer's batch number is scanned into the hand held stock readers upon reaching the store. Each individual unit is tracked by the checkout system. Provided "Bob Smith" paid with a credit or debit card (which happens for 98% of all large tech items) the store's own computer system links "Bob's" credit card number to batch number to manufacturers number. Any person or agency with access to these systems and some initiative would only need to do a few hours work to track a printer directly from the manufacturer to the person who owns it. Ain't technology grand?
Lftndbt typhonx6 years ago
In your country each product, has an individual barcode at POS? That's interesting. Over in AU each product has the same as the rest of that product. Hence no association with Item Id's/batch number and credit card details. So no problem there.
some products have more than one bar code. the generic one is used to pay for the product and the unique one to identify it in the storage rooms and when shipping now consider that a single shop does not sell lots of the exact printer. most people buy inkjets and not color lasers so a small or medium shop sells below 100 of the same model. the unique printers can be tracked up to the shop. from there there are only number of people as the number of printers to check and at wish this can be done manually based on other info the workers at the shop line can be required to scan both bar codes in which case the printer can be tracked down to a single some1 some packages and products also include RFID chip (wireless equivalent of bar code) which is unique too some pinters setup wizard asks to do 'online registration'. this is another way to get personal data bypassing the shop entirely. the combination of both can link a human to an entire computer (and not just the printer) thru the printer. this applies to many computer appliances not only printers
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LoL... Oh you make me laugh. Good day to your sir,. your antics have bought a smile to my face. ;)
any way I could get a transcript of that thread? or would the wayback machine have it?
ac-dc typhonx5 years ago
Actually no, the checkout systems generally don't keep track of individual unique serial number except on certain purchases. Most often they only scan the non-unique UPC code when you checkout. Thus, there may be a link from make and model of product to the credit card, but not any particular specimen of product.
JohnJY5 years ago
Now, I have an experiment. If this is the serial number ,then you could read it. But how, is the Big Q. Think about it, if a friend printed you a sheet and found the number and Googled it. Then the next day you could tell him his exact Printer, Number, Date of Made. Everything. What would freik you out more, tell you your printers spying on you. Or make them think your spying on them. Funny.
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Ha! I have no printer =3
cipris Uru Wolf5 years ago
lol me other ink cost too mutch so if I need a print out I print to pdf and then print it at kinkos lol
orangos5 years ago
How's this for a quick and dirty fix? Measure the dot pattern from your printer, then create a random dot pattern of your own using a similar dot size and grid spacing, then print it across your page along with the rest of your design. It won't be perfect but it could irritate the hell out of whoever's snooping on you. Or at least let them know you're wise to them.
fantacmet5 years ago
The UPC barcodes are all the same, but there are other barcodes some on the printer itself sometimes on the box, that are different. They are a barcoded serial number. Most everything I have purchased that is electronic has a barcoded serial number on it, that is not the UPC that is the same on every one of the same model of the product in question. Sometimes these get recorded with who bought it, sometimes they don't. I have enough identification and stuff though, I have no privacy, but it's by choice. I certainly understand why people would want their privacy though.
shadowman25 years ago
What about B/W laser printers.
mking20126 years ago
Welcome to the "post 9/11 age"
MicroKID6 years ago
You normally purchase items using your credit/debit cards. That is stored data which can be used to track your purchases (similar to Loyalty Cards -all used to collect your private shopping habits and dates and times). You may not know it - but all credit card companies have a file on your entire shopping profile. Welcome to the "information age".
Bam826936 years ago
You can get that blue light free! If you donate $5!
bwpatton16 years ago
I saw something about this on the news about 3 years ago! This is freaky. Everywhere you go you can be tracked. I wonder how long this has been going along?
Ward_Nox6 years ago
OK i just tried this w a black light led and i THINK i see something
although it is possible, it is unlikely because for that to happen your printer would have to have uv responsive ink. That would be an interesting facet to the conspiracy though. cheers, mspark400
Black light LEDs give off some visible blue-purple light. Under blue light, you're supposed to be seeing the yellow dots as black, not fluorescent.
flourescent? Or Fluorescent!
they were black the paper is all that floreced
the paper is fluorescent and the yellow ink (or paper with ink on it) is not. thats why you see dark dots on blue background and not bright yellow dots with the blacklight the paper will light too (in blue light) and the dots i think still won't
well when i hit a printed item i made w a black light i noticed some dark spots that didn't appear under any other color light (i don't have a blue led but i have red yellow green and blacklight i tried em all
Blacklight works but blue is better. Far better. When you shine a white light, the white paper reflects all the colors back. When the white light hits the yellow ink, the blue wavelengths are absorbed, making the ink look yellow, However the dots and difference in contrast are small. When you use a blue light from a LED or something, the white paper reflects the blue light, but the yellow ink absorbs that wavelength, making the dots look black. Because the contrast is large, you can see the dots much easer. Even more so if you use a magnifying glass While the existence of the dots have been an open secret in the digital printing industry for years, I didn't know how to decode the dots until the EFF came along. Each sheet of paper has (on my machine) the machine's unique serial number and the time it was run encoded on every single sheet.
well like i said i don't have a blue LED...not one thats handy but if you go to a store w some capsule machines there are some that dispense finger mounted led flashlights and i know there's blue ones
I'd also avoid staring at white paper illuminated by UV light for long periods of time.
zer66 years ago
Thats really cool.
I'm pretty sure I have the same scanner...I`M BEING TRACKED! (Queue dramatic music)
Well stop doing whatever it is that your doing that would make LE want to track you down. ;) Print you manifesto, anarchist fliers, etc. in BW on a BW only printer ;) No doubt the EFF is on DHS' radar, so now is instructables. ;)
awkrin6 years ago
isn't this violating the customer's privacy? after looking for dots for 10 minutes I decided my printer doesn't make any...
This is a method used by our government to help identify counterfeiters. Thousands of counterfeit bills show up every year that are just run off on inkjet printers.
Inkjet printers dont put the yellow dots; only colour laser.
Rainh2o6 years ago
Its a worthless tracking system. If I go out and buy a printer from out of town and connect it to a computer thats is not connected to the internet bought from another town, print money or whatever, all the FBI is going to know is that it came from an XXXX brand printer with SN#XXX. If I buy both at a garage sale or used computer place, with cash and carry, its unlikly they will take your name and addy IF it could be traced back to the shop, no telling how many hands they had been through before it got to mine. Wont help them much to track it down.
but should you get busted printing money or what have you - they would have an endless supply of charges to bring upon you. at least if you only printed 1 bill, you would only have 1 count of forgery, but rest assured they would keep track of all the found bills with that sierial number and if it's your printer that did it (and i might add at DIFFERENT times(since the printer also keeps track of the date and time)) then it's not just 1 count it's 40 now.
It SHOULD be 40 counts if you printed 40 bills. Are you saying that you should be able to get away with crimes as long as you dont get caught?
why not just add yellow dots at the correct placement on your document in order to ruin the encoding
110100101106 years ago
is there a chemical treatment that can show the dots in better contrast ? maybe microwave treatment ? (dont have an example page at hand to test)
jkyas6 years ago
Interestingly, the test data sheet specifically says "Send test sheets until Nov. 1, 2005" Is the EFF still collecting them?
EFForg (author)  jkyas6 years ago
Oops, sorry about that! Yes, we're still collecting them. That information sheet has an old date and I'll have it replaced.
the same guy uploaded the instructable to youtube too and there he states that yes (hey EFForg sorry for beating ur privacy)
Thanks, Ash.
dlewisa6 years ago
Would it be possible to make a random pattern of yellow dots in photoshop and overlay them on all documents that you print? If the specific pattern of a given printer was known then the photoshop pattern could be made to mimic and match it in an effort to hide the date and serial.
That's clever. Printing off a batch of sheets with the random dot pattern and then using them as normal might be less work than doing it in software for each document you print, though.
khendar6 years ago
How about just removing the yellow toner cartridge ?
randofo khendar6 years ago
That would make it even easier to identify you.
khendar randofo6 years ago
This is true. But then again, if you're the kind of person who worries about this kind of thing, you probably should be under government surveillance. Or at least psychiatric supervision. ;)
Please see my other comment about countries whose governments don't allow freedom of speech or freedom to assemble.
Judging by almost everyone single post prior to mine, you all seem to be a little too paranoid by this. WOO HOO! someone, somewhere can track that you printed a piece of paper. unless you're all up to something no good(in which case you should probably be stopped/caught) no one should really give a damn. it's not like Joe from accounting is going to go through the companies trash and look for every piece of paper that has your printers code on it.
You forget that there are other countries in the world that don't allow as much freedom of speech as the US does. In some places, you could get in trouble for, let's say, posting flyers that criticized a politician or advertised a meeting of non-government activists. Or downloading and printing out a banned book.
see 2 examples from my other post. nope of them involves the government the government (with access to databases that third party dont have) may use the system for any purpose - not necessarily protecting the people that live in its country anything from journalist docs to protest fliers to a grass joint can be tracked and nope of them normally puts people at risk. the journalist docs and fliers may actually reduce risk from misbehaving government
Good point, but there is a major flaw. Do you want people sitting around in your house all day watching you? Kinda the same concept here. Whats this to stop them from doing more than little dots on the page? We need to speak up so our privacy doesn't become nonexistent.
110100101106 years ago
Just wondering - can any kind of printer (black laser / inkjet) leave its touch in the page ? (for example in the dithering pattern of gray areas)
Yes all printers do this, just the b/w printers leave tiny black dots, instead of tiny yellow dots. As for your previous response, you COULD copy a blank white sheet on a high level scanner (lets say 3000 dpi or so) and select the dots by color, then copy them and make a layer with just those dots, then rearrange them as you like. For future projects just import your document into photoshop and add the newly created dot layer on top of the document, then flatten image and save. Walah, a nice document to print with a VERY confusing array of nearly unseeable dots.
i have black HP laserjet 1200 from 2001. were there dots back then ? if yes where to look in the page ?
Interesting, I've got the HP laserjet 1100.
EFForg (author)  110100101106 years ago
As far as we know, only color laser printers include a verifiable means of tracing a document back to its origin. At the moment we have no evidence suggesting black laser printers and inkjet printers produce codes of their own.
chopsuey8666 years ago
Does google something similar with their google earth images?
The strange thing>
When I make some google earth screenshots and then try to transform & combine them into a pdf, the pdf contains only blank white pages.
When I first transform the .jpg screenshots into .png files and then transform them into a pdf, I works without a problem.
The same thing with the photomerge function in photoshop.

OhEmGee6 years ago
I would love to try this but dont have any of the materials for any of the steps, but this sounds so conspiracy-ish. I kind of doubt that my printer has that because it is like older than me, its so old its like an antique(well maybe im over exaggerating)
Trebawa6 years ago
What if you were to print out blank pages, then turn them around and load them into the printer? You'd have two sets of dots, which together would form a different pattern.
mlmaynard6 years ago
Cool. I always knew they were there but never knew how to see them. Using a magnifying glass and a blue led flashlight they are all over the paper. Used a page that was about 1/3rd text and the rest blank. It is a Brother laser printer. Couldn't see them without the magnifier. Great job.
oooh now that's interesting!
Plasmana6 years ago
Wow... That is very interesting... Also, can you see the dots by exposing the printed paper in UV light?
i think yes with the led the paper is fluorescent and the dots are not. i dont think the difference between blue led and UV can make them fluorescent
Okay thanks!
wingbatwu6 years ago
I'll see it when I believe it!
randofo6 years ago
Well, the big question is, how do we remove them? I would imagine that altering a few dots would make the whole system useless. Perhaps we can include our own dots in everything we print. I mean, filtering the dots out seems harder than adding extra noise.
ElMarko6 years ago
Is this done at the driver level or is it in the firmware on the printer?
purduecer6 years ago
"Its free, that's right free, for a donation of only five dollars..." Interesting statement, don't you think? Either way though, interesting Instructable, good on you folks :-)
I think it was a joke... maybe
use an iclops to find the dots
ikahoshi6 years ago
I wonder if one could make copies of pages with dots, hence adding dots to dots, and perhaps befuddling anyone trying to ID anything using this system.
you need perfect matching (that aint gonna happen) and still the inks of 2 printers may be different in brightness you need to eliminate them or make something more brutal (and noticable)
I see. What about using the yellow ink to coat the page? Then there would be no way to distinguish between the dots and the masking treatment. It might be simple to get some yellow ink considering the cartridge refill outfits carry jugs of the crap. Make a homemade extra wide felt tip pen and give it a pass over the document. It would be ugly but it might do the job. Of course if I really didn't want to be traced I'd use someone else's printer/ copier. (evil laugh)
m1k3y6 years ago
Great job, guys! Thanks for helping get this kind of information out there.
The secret service knew about this for years. its to track counterfeiters. They can also take samples from the ink and link it up to a company and year of production. Even for ink pens (except for jells)
mossDboss6 years ago
thanks for posting this. Been watching this since you all first published an article about it.
Paranoid much? Seriously, nobody can really see it with a naked eye. Not to mention that the tracking helps police forces track down the origins of things like ransom notes. I have no problem with this, most of you should take off your tin foil hats and live a little.
Ward_Nox6 years ago
SO PISSED OFF! as a graphic artist the idea of printers adding little dots to my printed work pisses me of on several levels
Where's the link to print a test page on the EFF site?
EFForg (author)  rachiepalooza6 years ago provides links to test sheets.
mrmath6 years ago
You're only paranoid if you're wrong.