@renatoram @vkc That might be the reason to use them in post offices and the like.
Sadly, when I was starting my new bank account last year, they just printed two copies of the paperwork on a laser, and why wouldn't they, it's fast as heck.

@vkc

Or just print out random yellow dots on the pages first, then feed it back in again for the print run.

@vkc @Kiloku As a kid, a friend and I ran a small neighborhood newspaper. We talked businesses into advertising in it, and distributed it in a maybe 10 block area because many people needed birdcage liner, and also because who didn't want to read a review of a TV show by a kid?

We talked the bowling alley into letting us use their mimeograph machine in exchange for an ad placement.

Mmmm. Mmmmimeograph smell.

@vkc Thank you. The Wikipedia article helpfully refers to software to help remove the pattern before publishing scans and thwart recognition of your printers pattern by adding a mask before printing https://github.com/dfd-tud/deda

@ozzelot @vkc

But I believe the impacts could be analysed and compared instead.

Buy a spare print head and bury it in the forrest, when not printing secret stuff.

Keep lots of example of printing with your normal print head.

@ozzelot @vkc used to be (at least in Italy) that two copies that were not the result of a single unique action weren't legally considered actual copies, I believe.

Plus, yeah, when printing hundreds of invoices in the early 2000s it was probably faster and cheaper (I remember pre-printed forms of continuous paper that would make 5 copies in one go).

@ozzelot @renatoram @vkc

Shipping companies still use them but it is becoming increasingly rare even amongst them (CMR form if memory serves me right)

Fun fact: I used to work at a call center supporting software that allowed printing those forms. I can't tell you how many little tips for resolving printer issues we had - but rarely if ever had genuine unsolvable defects. And if something broke, replace the part *maybe* recalibrate and off you go

@vkc Related: a lot of things labelled as "fax machine" can actually also function as stand-alone USB printers. And "fax machines" are often free on classifieds, and use cheap generic cartridges/toners, and (aside from stuff like doorbell cameras) that means there's basically no paper or money trail from the original purchaser to you at all.

It's not a bad way to get hold of a more or less anonymous printer.

@Aprazeth @ozzelot @vkc good old 120 columns Brother printers... They'd shake the table like a washing machine

@vkc The dot decoding was used in episode of The Night Agent, so hopefully awareness is increasing. Good reason to use a mono-only printer where possible.

Each of these leaks shows just how broken classified document handling in the USA is.

@SuperMoosie @vkc this is a toolkit that can do exactly that - https://github.com/dfd-tud/deda

@vkc Alternate solution, maybe: get 3 printers, print a bunch of tiny yellow dots randomly on two of them, then the actual document on the third.

Assuming the printers put the data in the same place every time, that should corrupt it, I'd imagine.

@mausmalone I was thinking something like that, but I'm imagining you need three of *the same model printer* in order to sufficiently deal with it. Alternatively the encoding might be robust enough to detect through that.

@vkc
Maybe becouse of that is why you can't print in black if you dont have color ink?

@vkc yes. as a privacy person, our personal opinion is that you should assume all modern printers have a system of this nature, although it hasn't been a focus of active research in some years

@vkc @ozzelot I would think it has tool marks that would be identifiable but not serial numbered.

@vkc Sometimes I want to make a CUPS compatible plotter using steppers and a bic pen.

@socketwench yes!!!!!

@vkc @ozzelot You can also just use a black and white laser printer instead of a color one...

@steter @vkc @Kiloku
When I was a kid my mom was a school teacher. She made her own mimeograph gel in a cookie sheet and printed handouts and tests for her classes. I’d help her with the very laborious printing, laying one sheet of paper down at a time and gently brushing the back of the sheet with a ruler. Then you peel it off and lay it down on the ping pong table.