Each Canon PG-512 contains one or more ink reservoirs. It also has electronic contacts or chips that communicate with the printer, and uses a thermal ink jet. Each partition of the ink reservoir contains a heating element along with a resistor or a tiny metal plate. The printer gives a signal to this part and tiny electric current flows through this resistor or metal part making it warm. The ink in contact with this resistor is vaporized into a tiny steam bubble inside the nozzle. As a result, ink droplets are forced out of the cartridge nozzle on to the paper. All of this takes a fraction of a millisecond and is repeated thousands of times.
The quality of printing depends on the effortless flow of ink. But this can stop when the ink begins to dry at the print head which can happen when ink supply is low. The dried ink can be cleaned off the cartridge print head by gentle application of isopropyl alcohol. However isopropyl alcohol has the side effect of damaging the printing head and melting the plastic at the connections. A better alternative is lukewarm water which is 90% effective. In this regard, the original Canon cartridges have a very good performance. w