Most likely it tries to print rich black, which uses color to make the b&w printout look better ( and use up all that costly color). You can disable that in your printer settings with most printers.
I heard that before, I think it's a tactic to bully people into buying more ink they don't need. Ensuring tracking dots is maybe just an unfortunate side effect.
I've always assumed that is just lazy design (some resources that _might_ be needed are unavailable, report and refuse to print withut checking if they are actually needed for the current job) rather than due to a security (or even ink selling) measure. I've seen the behaviour as far back as the first colour photocopier I ever used.
I've seen that as well a long time ago on a black+red photocopier, no yellow and probably no tracking patterns since red would have been quite visible.
I would also be interested in a citation, but it does make sense; if tracking dots is well known (which they are), and it was easy to circumvent by just removing yellow toner, anyone somewhat technically adept would just remove their toner before printing their illegal documents.
This makes less sense than you might think because the original motivation from the government side was tracing counterfeit currency, not tracking all documents. Printing convincing counterfeit currency without yellow toner would be a challenge!
However, the governments did not succeed in limiting their technology to use in counterfeiting investigations, and may not even have attempted to do so.
If that's true that just makes me angrier because a far better solution would be to improve the currency, like Canada and many other countries did long ago.
My Epson does this, and it's apparently because not having enough ink in the system leads to maintenance issues with heads drying out, etc. Which is understandable, but I wish there was like a 48-hour override so running out of a color didn't prevent me from printing the documents I urgently need RIGHT NOW. So instead, I have to purchase a couple hundred dollars worth of cartridges in advance.
I'm not so sure about that. Having had an inside view into one such program I can say confidently that at least in that particular major manufacturer's situation, that had absolutely nothing to do with it. It was entirely engineering-driven and about preserving the print head.
That doesn't make much sense to me. B/W only (not greyscale) is currently understood to not output these dots at all, so why would the presence of yellow matter?
