I bought a set of JetSir ink cartridges. A month or two later the print head clogged (cyan and magenta). I'm not sure the problem was the aftermarket cartridges, though; I don't print every day, and when I do it's usually text (black and white). HP's print head cleaning function didn't fix the problem (but it sucked a lot of ink out of the cartridges). I successfully cleaned the head manually, but later I had black bleeding into the other colors. I can't see how that could be caused by bad ink. Maybe I didn't get all my homemade cleaning solution out of the head. I ran HP's first level print head cleaning function a couple of times and it seems ok now.
I also bought an ink refill kit, which I'll try when the aftermarket cartridges run dry. Or, more accurately, when HP says they are dry (the printer keeps track of how much ink it thinks is left, probably to avoid running the head dry, which would damage it).
A set of four OEM high capacity cartridges for my HP Officejet Pro 8600 printer cost more than the printer, and I don't get as many pages out of a cartridge as I should because the printer dumps a lot of ink into the diaper after every print job (ostensibly to keep the head from clogging). I'll continue buying aftermarket ink, either cartridges or refill ink, until the print head is toast.
