Canon imagePROGRAF iPF6400 - Manual (Page 844)

Before print jobs and maintenance that consume a lot of ink
If little ink is left, there may not be enough for large-format printing, head cleaning, and maintenance, which require a
lot of ink. Replace or prepare to replace the Ink Tank.
If a message for ink replacement is shown on the Display Screen
When ink runs out, the Message Lamp flashes, a message regarding Ink Tank replacement is shown on the Display
Screen, and printing is disabled. Replace the Ink Tank at this point.
When to Replace Ink Tanks iPF6400
User's Guide
Maintenance and Consumables
Ink Tanks
844