The Jobs on Printer accounting pages show that printing has used 220 mL of ink in the 3 mo. I've had my 8300. However, the "File/Show Ink & Paper Consumed" gives total ink consumed as 718 mL. Is this roughly 500 mL discrepancy about what one should expect? How much of it is from charging the lines and how much is from any automated head cleaning? I leave the printer on all the time, as I do some printing at least every week, and have not yet needed to manually run a head cleaning operation. Thx