Most CIS require tubing because of the moving parts the cartridges sit into. However, for models that don’t require the cartridges to move back and forth from side to side, tubing is not necessary and can be eliminated from the CIS system by combining the tank and cartridge into one.
What is the concept for a “CIS” or Continuous Ink System and why do Brother CIS systems not require tubes and external ink chambers?
A CIS or Continuous Ink System is exactly what it sounds like – a system that is designed to feed continuous ink supply to your printer without the need to change cartridges. The “system” comes with a lot of ink to start (usually, 4-10x the amount of ink found in a regular ink cartridge), and it also comes with a mechanism to keep the ink flowing (through a refill port, so you can keep adding ink without needing to change cartridges).
Brother printers are made a little differently to other popular printer brands such as Epson or Canon, and the main difference is that the cartridges inside a Brother printer are STATIC – that means, they do not move like they do with Canon or Epson. In Canon and Epson printers, the cartridges move from left to right as they go over the paper. With Brother, the cartridges DO NOT MOVE. Therefore, there is a practical difference in the design of the CIS for Brother vs other printers. Since the cartridges move inside other printers, the continuous ink system also needs to “move”. Hence, CIS systems for Canon and Epson have tubes, which move with the cartridges as the cartridges move, and they feed off of external ink tanks. Since Brother cartridges do not move, tubes are not needed to be a part of the CIS, and so external ink tanks are not needed. Therefore the CIS for Brother is not external. The Brother CIS system is essentially composed of oversized cartridges that hold 4-10x as much ink as regular ink cartridges, and are designed with refill ports so you can add ink to the oversized cartridges. In many ways, this is a better system than having external ink tanks and tubes.