A recycler can simply refill the cartridge with toner or remanufacture the cartridge by replacing the drum and a few other components with new ones. The recycled cartridge is usually quality tested too. Some inkjet printers use ink cartridges that you can refill yourself. If you're deft with your fingers and don't mind a few stains you can buy kits for refilling these cartridges. This allows you to refill just the colours you need and cuts down on printing costs.
Some manufacturers say that optimal results can only be achieved with their consumables.
Using recycled cartridges will not automatically invalidate a printer's warranty. Buy consumables from a reputable source that will stand behind their products. Inc. All rights reserved.