Lets first look at how they work.
The printhead and circuitry which perform most of the work of the ink jet printer are contained on the small ink jet cartridge itself. Each nozzle or jet is smalller in size than a human hair and each is backed by a heater or resistor which heats and cools the ink inside the cartridge. When the ink is heated, a bubble forms. These dots form the characters on the page at the rate of up to 6000 drops per second. The heating and cooling process is happening at very high rates of speed, too.