The printer has an refillable ink reservoir unit 24. The reservoir unit has a valve 64. The valve opens into a pressurised chamber 56. The chamber is put under pressure to close the valve and prevent ink flowing out of the reservoir. When the valve is open, the ink flows via an outlet 28 from the chamber to the reservoir. The ink is fed from the outlet to the reservoir at a sufficient rate to keep the pressure in the chamber low enough to prevent the valve shutting. The reservoir module is located in a chassis 22. The chassis has a hard protective housing on the underside 30 and has a fitting 32 for connection to the pump 26 and has outlets 36.
