Are you powering your printer off when it is not being used?
If yes, then that may be the problem.
The printer has a self-timer that knows how long it has been since the last cleaning cycle. If left on 24x7x365 it will periodically run a very light version of a self-cleaning cycle just to get anything in the nozzle purged out before it clog. This uses just a few drops of ink.
If the printer is powered down, the self-cleaning timer doesn't run (there's no internal battery, etc.) and the printer has no idea how long it's been since the last cleaning -- and I'm told this results in it wanting to do a more aggressive version of the self-cleaning cycle and that does use quite a bit more ink.
I leave my printer powerd on all the time. Once every few days I'll hear it wake up and do it's thing... then go back to sleep. But it seems to take a long time to empty a tank doing this (it's not much ink). I pretty much only use my printer for photo printng, so the non-photo tanks (such as matte black) almost never get touched. I use them as a mearsure of how quickly the self-cleaning cycles go through ink. My printer is a Pro-10 and uses pigment based ink (the Pro-100 uses dye-based ink). Pigment ink dries faster than dye ink ... so pigment printers need more frequent cleaning. I think the Pro-100 waits twice as long as the Pro-10 before it self-cleans. But even with the more frequent cleaning... my guess is it would take around a year to empty a tank via the self-cleaning method.
Tim Campbell
5D III, 5D IV, 60Da
