It always pissed me off that ONE color ink would run out and I had to replace the whole 3-color cartridge on my H-P printers. Went into a “Mister Ink” store here and inquired about cartridge refilling ink. They only sold ‘refurbished’ cartridges from the factory, still pricey. The store owner said he didn’t sell refill ink anymore as the manufacturers had thwarted that by installing smart chips in the cartridge that monitor the level of ink. The cartridge shuts down if you squirt new ink into it. He said it takes a good hacker to reset the chip in the cartridge so it can be refilled, so he gave up trying to fight it.
He recommended BROTHER printers that have individual color cartridges that allow you to change out just one color at a time if it runs out…. a bit more sensible. But the days of ‘easy-squirt refills’ of printer cartridges is over. That’s the ‘continuing revenue stream’ for the makers, and they will protect it aggressively.