The turn-it-off-or-leave-it-on question has been hotly debated for ages. I don't think there's a clear, in-general answer. I'm not convinced it matters for Epson printers. Keeping humidity above 40% is more important.
What you can do for an R2880 is get some refillable cartridges from InkJetMall and a large bottle of their Piezoflush, and put flush carts in when you're not printing and put the ink carts back in when you want to print. On printers with small, on-head cartridges it's a quick and relatively inexpensive switch. A couple of head cleans in either direction and you're set. If you do this often enough you'll probably also want a chip resetter for the refillables.
While this is still possible on printers with larger, off-head cartridges, such as the 9800 Paul mentioned, it's a much more expensive switch as you waste much more ink and flush each cycle. But some people prefer that to the alternative.
I use my printer infrequently and I just spent a fair amount of money getting my Epson 2880 printer head cleaned professionally after the nozzle cleaning utility did not work. I know I should print more frequently to keep the printer head clean. However what is the best practice: Should I turn it off if I will not be using it for a couple of weeks.... or leave it on? I have heard both versions and I am not sure what the logic is for either version.
