@buherator I'm told that Brother is more friendly than HP and Canon regarding ink supplies.
@buherator My guess on this is that many tech savvy people try to get rid of printers for everyday tasks, leaving only a small community of print enthusiasts, and that is further fractured into the wide range of possible shapes (@th is doing plotter scale stuff with what may even be open hardware; @haraldgeyer is more on the producing-a-book end of things, and there's a huge space in between even without getting started on colour).
@chrysn @buherator @th
I have been looking into this some 15 years ago, as commercial printer firmwares don't support my requirements.
One thing about laser printers: Even HP wasn't producing the actual printing parts themselves. They import from Japanese companies, that kind of invented it. You could probably buy the same parts and make the rest open-source fairly easily.
Or you pick a popular model (available 2nd hand in quantity) and design an electronics replacement kit for that model.
@buherator @chrysn @th Before each ink cartridge had a chip with an usage counter, it was quite common to refill used cartridges with cheap ink from independent suppliers. (A rather messy task and not sure, how much money we saved by that.)
However that was ready made ink from cheap(er) sources. I don't know anything about making ink yourself. I guess, you at least would need to be careful about health safety during production: Pigments are very fine dust, that you probably shouldn't inhale.
@buherator @chrysn @th Of course, one of the benefits of a custom firmware would be, that you can disable such refill checks...
@buherator Oh my goodness, people have worked on this. Here's just one example. https://stackoverflow.com/questions/36674210/converting-bmp-image-to-set-of-instructions-for-a-plotter
I might have to dig my old HP plotter out of my basement.