Tiny pores, which allow for a heated ink bubble to travel through as it cools. Print head nozzles are vital to the proper functioning of a print cartridge because they are located on the print-heads and can easily get clogged or worn out due to friction if printed with when the cartridge is dry or out of ink. In the remanufacturing process, 123 Refills pre-inspects all nozzles for defects using an electrical test. If all nozzles are electrically OK, the cartridge then gets cleaned and the nozzles are ultrasounded and steamed to declog them. In general, most of inkjet quality problems are due to defective or worn out print heads.