Samsung ML-4512ND-XAA - Manual (Page 222)

Storing the toner cartridge (or imaging unit)
96 5. Maintenance
Samsung’s printer warranty does not cover damage to the
machine caused by the use of a refilled, remanufactured, or
non-Samsung brand toner cartridges.
3
Estimated cartridge life
Estimated cartridge life the life of the toner cartridge (or imaging unit
yield) depends on the amount of toner that print jobs require. The
actual print yield may vary depending on the print density of the
pages you print on, operating environment, printing interval, media
type and/or media size. For example, if you print a lot of graphics, the
consumption of the toner is higher and you may need to change the
cartridge more often.