Make sure you purchase the right ink cartridges for your specific printer and printer region or have your old ones refilled. Cartridges are not compatible between different brands, and often not within the same brand. Unlike other inkjet manufacturers, HP often designs its inkjet hardware to use country-specific consumables. When you unbox a new HP inkjet printer and set it up, you install a set of ink tanks that ship with the printer. As you turn on the device and get ready to use it, an initialization sequence localizes it to the country associated with the ink cartridges you installed. HP recommends that you use Original HP ink cartridges. XL (Extra Large) cartridges cost more but do provide better value in the long run. They will be able to print about 3 times as many pages as a regular cartridge. Our advice is that if you print often, go with XL. However, ink can dry up. So if you are not a frequent printer, go with the regular cartridges.Ink level warnings and indicators provide estimates for planning purposes only. When you receive a low-ink warning message , consider having a replacement cartridge available to avoid possible printing delays. You do not have to replace the cartridges until the print quality is unacceptable. Use the single-cartridge mode to operate the HP All-in-One with only one print cartridge. The single-cartridge mode is initiated when a print cartridge is removed from the print cartridge carriage.