The inkjet cartridges we sell have been used before and we have cleaned them and refilled them to their maximum amount. Because they are used and because we fill them to their max, the measuring chip on the cartridge will no longer work correctly. Allow me to explain why...

Once a cartridge has been used, the measuring chip usually will remain at "empty". Sometimes we can "reset" the measuring chip, but this still produces an inaccurate measure because it only measures what is used in printing. The chip cannot tell how much ink is actually in the cartridge. So HP sets the "full" measure on these chips at the amount of ink they fill the cartridges with (often only half way), and once that much ink has been "used", you are told the cartridge is empty. But since we fill them all the way (often twice as full as HP), the cartridge actually has a lot of ink left in it.

So how will you know that it is empty? When it quits printing.