In present day laser printers we use mono component toner. The ink or the toner is magnetic material so its sticking to the magnetic roller in the toner module. Earlier days and present day high volume printers do not use magnetic ink. There we use two different materials or dual component development. The toner is carbon particle and non-magnetic. The developer is ferrous material it sticks to the magnetic roller and the carbon powder sticks to the developer due to electrostatic charge. This developer is used only as carrier and never exhausted. This developer and toner mix is called developer mix.
