The ink-jet nozzles are small apertures in the front of the ink-jet print head. These nozzles are replenished with ink from an attached ink bladder. Thermal or ~piezoelectric~ elements on the sides of the nozzles selectively force ink droplets out of the nozzles and onto paper. The droplets are sent out as a very rapid jet or spray of ink. The order in which the nozzles are fired determines the image or character on the page. A drawback to this otherwise high quality technique is that it requires a water-soluble ink, which is prone to smearing.
