Can a letter be traced back to a computer/printer?

Hi all, I have a character who receives a letter from a kidnapper. It’s typed up and was obviously printed somewhere. Can the character trace the origin of where the letter was typed, or which printer it came from? (assuming she has a super tech-savvy IT specialist who can help her).

No. Once it’s on paper, it’s impossible to trace.

Printers aren’t like guns where they leave behind a ballistic imprint that’s unique to that specific gun.

The character could go around to every printer they can find and reprint all the logs to see if they can find the document name used, then maybe find the IP it was sent from. But if it was connected via USB, there’s no way to trace, and that’s assuming the kidnapper is using a publicly accessible printer, or they work in the same office/company.


Yes. Very easily.

The printer type it came from and the date it was printed AND the serial number of the device are all in the document, just gotta find them :upside_down_face:
Looks something like this, every colour printer on earth made since the early 90s does this


Ah good sir but they are like guns if your printer was made after 2004 there are tiny dots, no more than a millimetre in diameter, which act as an identifier of the printer’s serial number and the date and time of the print.

It’s been in Quartz computer magazine there was a case someone from Nasa was arrested it’s how the feds find kidnappers it’s truly old business

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yes… this
why must people talk of what they do not know -_-

I don’t think it’s like “Open” info like I probably wouldn’t know if my job wasn’t to know useless things I would assume unless someone is into computers they wouldn’t know it’s kind of silly if you think about it tracking paper like who would think that up

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actually: police …for kidnapping cases for example :rofl:

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my Issue is just dont speak if you dont know, assuming hurts everyone
just spreading missinfo for the hell of it
2019, you have google
no excuses besides thick-headed laziness
im supper offensive

I feel like local police don’t have the resources like think about it they’re backed up on DNA im unsure if they can access microdot data and I suppose a way around this (Dont quote me if you’re going on a crime spree) would be to photo copy that same letter 10 times so the dots overlap then you would need Nasas MDT in my theory

Ah but google can tell you lies (and is also tracked like I LOVE google not allowed to use it on work devices we use Bing I hate bing)


back to OP: you have as well many types of ink - and ways how it is applied, the paper can be “dirty”… But, personally, I think all that is awesome to prove that “the letter came out of this printer” - while being hardly useful in your attempts to find any suspected printer first.

Yeah true but at the same time,
People just run around spewing what ever their head cannon is
Even if its literally the oppisite
As in first reply

Its annoying and not helpful to anyone

When I ask a question about quantum physics…
I don’t want some random with no back ground in quantum physics to explain their loose head cannon to me

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Thanks! Are these tiny dots on every printed paper? So if someone scanned them into a computer and knew how to do it, they could trace the data of the original print from the dot data?


Yes I’m ideally trying to get the characters to determine which printer it came from. If they had a list of printer ID’s, say in an office block, could they compare the ID of the printer the letter came from with that list of printers in the office?
Or something like that?

Ok cool so that microdot data can be traced if someone had the means to do so? So they could scan the letter and find the data in the dots and determine when and where it was printed? Or have an approximation of that? Thanks

interesting, sorry for adding question but even if we can find from which printer the letter was printed, how can one be sure from Where it was printed.

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Cannot determine where
Just when
The type of printer
And its serial number

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Re. printer steganography, there’s an article here

A few, less common, Asian printer models are still available that don’t leave these traces, according to EFF tests: here’s a page that’s no longer updated:

They’re rare enough that the kidnapper would have to be informed and deliberately careful to have one of them.

If the kidnapper had been lazy and used any modern printer, the dots would allow the police (but probably not an amateur) to trace the printer to the shop that sold it, and to the credit card that bought it.

If the kidnapper were careful, there would be no dots, and tracing would be more difficult.

Even without dots, once the police had both the letter and whatever printer and ink cartridge produced it, they would likely be able to prove that the printer did indeed produce the letter. Contrary to what one poster said, forensics is often able to identify the ink jet head that produced a print sample, even without the dots. The reason is that the production of the ink jets is not a perfect process, so every head ends up being slightly different than others, so it leaves very slightly different patterns of dots.

Other techniques include looking at the effects of imperfections in the paper-handling rollers mechanisms used by the printer. Many defects produce a characteristic, reproducible effect on the final printed product, that forensics can detect. It isn’t guaranteed, of course.

The main problem, as another poster mentioned, is that the dots and defects don’t tell the investigator where the printer is located.

If the kidnapper is really sloppy, they used a modern Internet-enabled printer that registers itself with the manufacturer for the purpose of diagnostics or ordering ink. In that case, the printed letter would tell police exactly where the printer is :grin:


Maybe if you had a list of suspected printers, say from someone’s home, you could match the ID of the letter’s printer with the ID of the suspected printers? I’m guessing something like that would be possible if you had one ID to go on, and a list of suspected IDs.

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