Toner cartridges differ from ink cartridges in that they contain toner powder.  Usually more expensive than ink cartridges, toner cartridges contain a fine, dry powder mixture.  This mixture is made up of the ingredients of carbon, plastic particles, and colouring agents.  During the copying process, the toner powder is electrostatically charged by a drum unit.  As the toner gets transferred onto the paper, the heated rollers of the printer fuse the toner onto the paper.  Brother, Cannon, Dell, Epson, Oki, Samsung, HP, and Lexmark are among the popular toner printers.  Toner powder differs in formula and quality among name brands, as does the toner particle size and fusing temperature.

What do you do when your printer runs out of toner?  Some owners actually throw away their entire printer and purchase another, as the cost of a combination toner and drum refill may cost more than a new printer.  Generally, a toner cartridge will last through about 2,000 printed pages and a drum unit around 40,000 pages.  Printer manufacturers make genuine replacement toner cartridges.  These are more expensive than refills, compatibles, or remanufactured cartridges.  However, they usually bring about the best results for your printer.  Cartridges for different printers are incompatible, either electrically or physically. 

Compatibles are available at a cheaper price than genuine toner cartridges.  You may also purchase genuine replacements from a specialist retailer.  Compatibles, which are also known as generic or alternative, are manufactured from scratch.  These are not exact copies of the original, as patents restrict the exact copy of a design.  Refills and remanufactured cartridges are less expensive, but have been used and refilled or remanufactured.  It is always environmentally responsible to reuse and refill cartridges.  Approximately 7.3 litres of oil are saved when a cartridge is reused.  Oil is used in the plastic of a new cartridge, and burned in the manufacture of new cartridges.    

Source by Ron Wilkie