A bulk ink bag system in a composite-based additive manufacturing process (CBAM) keeps the inkjet heads (cartridges) on printers filled to the proper level of fluid at all times while the process runs. The system includes gravity fed fluid delivery without requiring pumps; is simple to connect and disconnect to system plumbing; has the ability to change ink bags without interrupting the print job or introducing air bubbles into the ink supply; and has the ability to disconnect partially used bags and reconnect them later.