Abstract: An ink jet carriage assembly for an off-axis ink delivery ink jet printer including a movable print carriage; a plurality of ink jet printhead cartridges removably supported by the movable print carriage having cartridge septums for accepting respective ink delivery needles; a humidor structure located adjacent the cartridge septums for collecting ink from ink delivery needles when air is purged from ink delivery tubes connected to the ink delivery needles, and for containing or enclosing the ink delivery needles to prevent ink evaporation from the ink delivery tubes. A dummy cartridge collects ink from an ink delivery connector when air is purged from an ink delivery tube connected to the ink delivery connector.