How to tell if printer cartridge is empty?

If the paper comes out without any print on it, the cartridge must most probably be empty.. Even after doing maintenance, if the paper comes out without the print, it is almost confirmed.. The number of prints vary from one cartridge to another and from one company printer to another. Ur dealer might tell u the approx. number of pages that u can print with that cartridge can also be taken into account while checking whether the cartridge is empty or not...|||I pick it up if it feels light it must be empty most ink cartridges do about 400 pages before they need ink. hope that helped.