Provided is a printer assembly having a refillable cartridge assembly. The cartridge assembly includes an elongate main body defining a number of rectangular ink reservoirs along a length thereof, with end reservoirs being larger than reservoirs interposed between the end reservoirs, said end reservoirs being configured to store ink more readily consumed during a printing process. The cartridge assembly also includes a lid assembly covering the main body to seal ink inside the ink reservoirs, the lid assembly having an actuator to actuate a cartridge refill unit. Also included is a printhead assembly fast with the main body and operatively fed with ink from the ink reservoirs in the main body, as well as a refill unit engageable with the lid assembly to refill at least one of the reservoirs.