Canon PIXMA G3270 / G3272 MegaTank
G3270/G3272 refill care: match GI-21, cap the bottles, and preserve the ink path
Canon’s G3070 series documentation applies to G3270 and G3272 and identifies GI-21 refill bottles. These machines are not cartridge printers: ink is replenished into built-in tanks, then delivered through a tube system. Supply selection, tank-level checks and handling during refill matter because a mistaken bottle or spill can damage the printer or create a separate print-quality problem. Canon’s owner guidance gives the bottle codes and troubleshooting sequence; it does not authorize opening the ink tubes or manually priming the printhead.
This note is about routine consumable care, not a recommendation to refill at a particular interval. Use the tank windows and the on-screen estimate together, and refill before the level falls below Canon’s indicated minimum. After filling, close the cap, wipe only an external spill according to the manual, and confirm the tank contents are the intended color. If a color stops printing after refill, assess the nozzle-check pattern and follow Canon’s staged maintenance rather than assuming the bottle is defective.
Identify the exact family and bottles
The Canon G3070 online manual lists G3270 and G3272; its ink reference specifies GI-21 for pigment black and GI-21 for cyan, magenta and yellow. Check the complete bottle label against this family page before opening it. Canon recommends using the correct genuine bottle and printing or noting the bottle number when shopping. Do not substitute GI-20 from the G6020 family; visually similar tank printers can use a different generation of ink.
Check each tank before refilling or maintenance
Review all four tank windows, especially if a print shows one missing color. Canon’s cleaning and troubleshooting steps require checking remaining ink before deeper maintenance. If a tank is low, refill before any system operation that consumes ink, observing the fill-line in the owner guide and preventing overflow. A high reading in three tanks does not compensate for a low fourth tank when a color-specific pattern is defective. Record the approximate level and date if you are investigating a recurring drop or leak.
Refill deliberately and keep ink out of the wrong channel
Set the correct GI-21 bottle at the matching color tank and follow the G3270 manual’s cap and filling procedure. Work slowly on a stable surface, do not squeeze or force a bottle if the tank opening does not accept it, and avoid mixing colors. Close tank covers and bottle caps after refilling. If ink spills onto the cabinet, use the model’s cleaning instructions for external surfaces; do not wipe ink toward electrical openings or open the printer to reach internal tubing.
Use the printer’s own level and pattern signals together
Canon’s G3070 support distinguishes ink level from nozzle condition. The pattern identifies whether ink is actually printing in expected lines; the tank status indicates supply available. A full-looking tank with missing nozzles calls for the pattern-led maintenance path, while a low tank should be refilled before deeper cleaning. If the estimated level and visible tank disagree, consult the manual’s reset or ink-status guidance instead of forcing an estimate to match the window.
Treat cleaning and Replace Ink in Print Head as separate actions
Canon describes Cleaning and Deep Cleaning in the IJ Printer Assistant Tool, then a later Replace Ink in Print Head procedure for persistent air/ink delivery concerns. Deep Cleaning uses more ink and should follow two standard cleaning attempts. Replace Ink in Print Head is a separate system operation; read the exact guide and do not start it casually after a normal refill. Canon says some air in the tube can be present without affecting output if the nozzle pattern is correct.
Store and report supplies by part number
Keep the bottle label or a photograph of it until the refill is complete. For a support request, give Canon the G3270 or G3272 name, GI-21 color and whether the issue began before or after refill. Include tank levels and a nozzle-check pattern. This helps distinguish a supply mismatch, empty color, air-delivery symptom or unrelated print setting. Avoid buying a different bottle based only on “Canon G-series” because the exact family listing establishes GI-21 for these models.
After a refill, close both the tank access cover and the bottle cap, then check the nozzle pattern before replacing any part. A visible external spill should be cleaned only from accessible surfaces using the owner manual; do not reach into the tube path or soak the printhead. Keep the GI-21 receipt or package label with the printer records so future refills use the same explicitly listed ink family.