HP 45 Thermal Inkjet Cartridges have tiny pores (a.k.a. nozzles) that are easily clogged.  This is true for both new and remanufactured cartridges.  HP suggests proper handling procedures for cleaning and wiping cartridge heads.  These lint-free cartridge wipes will help your cartridges fire their best and reduce both cartridge failure and print quality issues.  50 Lint Free Cartridge Wipes (12X12) per bag.