An ink delivery system for an inkjet printer has an ink supply tank and a pair of printheads located at different heights. A primary ink delivery circuit delivers ink to a pair of intermediate tanks, each tank maintained a precise distance below a respective one of the printheads. Ink is pumped to the higher tank to the level of a weir and overflowing ink flows under gravity to the lower tank. The overflowing ink fills the lower tank to the level of a weir and overflowing ink returns to the supply tank. Secondary ink delivery circuits have capillary lines for supply of ink from each of the intermediate tanks to the respective printhead. Ink is maintained in the supply lines ready for inkjet printing by establishing a negative pressure between each intermediate tank and the respective printhead.
