The main element of toner cartridges and printer supplies for laser printer is photo cylinder: it forms a visible image of toner, which is then transferred to the print media.
To begin with, that all cartridges are calculated by producers in the different number of prints A4 but have photo cylinders approximately of the same diameter. Accordingly, the cartridge for 2500 prints A4 size at 5 per cent of the leaf, photo cylinder until runs out of toner will make about 15000 rpm with a light cycle. In toner cartridges for 5000 prints photo cylinder will turn in about 30000 times, exposing itself to friction of the cleaning devices and print media. Naturally, the surface of photo cylinder undergoes a twofold mechanical stress in the form of the friction surface. In the latter case, the cartridge can’t be filled without loss of print quality, more than once and it will recover, that is to replace photo cylinder.
The great importance in the work of toner cartridges and print supplies also plays the quality of paper you use for printing. Paper with low cost, and accordingly has a lower quality characteristics. Having sanded surface, it increases the wear of photo cylinder. Sanded surface of the paper sheet pollutes with the dust not only the apparatus, but also mixed with the toner particles and atmospheric dust in the raw printer and forms an abrasive, which scratches the surface of photo cylinder, that some time will need to restore the toner cartridge.
So, to summarize. On the number of cartridges refills influences:

1. Cartridge, declared by the manufacturer. More than the stated resource, the less refills cartridge without loss of print quality or no recovery.
2. Low quality media reduces the number of viable cartridge refills.
3. Lack of regular maintenance of the printing device also reduces the amount of refills without loss of print quality.

In each case it will be useful master consultation, which will diagnose and tell you what toner cartridges and printer supplies you need to refill or recover. But even if photo cylinder and other parts are worn out, recovery is still more profitable than buying a new device. After restoring the quality of high-quality print cartridge is almost the same as the new device.