Are they both inkjet printers? Most of the newer inkjets will turn off or go into sleep mode when they aren't in use so there shouldn't be a big difference in ink usage if it does that. How old are the printers? Do you know the model numbers?

Both my HP7760 and my wife's Canon AIO stay on 24/7 with no ill effects. As Bpgreen notes above they go into snooze mode.

Normally leaving a printer on will have no ill effect on its operation or the life span of the ink cartridge. An actual curse to inkjets is lack of use. The heads will tend to dry up and start to clog.

I like Janette have two printers, a good one and an inexpensive all-in-one, which I truthfully don't use all that much. I do try to remember to print a sample page every few weeks if I haven't used them.

If you are like me and have the printers defaulted to greyscale and fast print remember to manually reset them to normal so the color cartridge is used also.

DA

When I click print it will come on by itself, then I turn them off at night when I turn my PC off. I have been using printers since 1996 and haven't had a cartridge dry up. I used it a lot in the beginning, but not anymore and still no problem.

Another thing to consider, some cartridges are small...meaning they contain less ink. I think mine are 7ml, enough for 190 pages.

Pam

I was told several years ago by the IT gal at my former job that it does dry out the ink if you leave them on. However, it has been almost ten years since she was in college for computer science and machines may have changed.

Thank you everyone for your responses. I just got back to the computer. Here are some answers to your questions.
They are both inkjets. The oldest one is a Lexmark Z705. It is color and black, but I only use the black ink now since I got the other one. I don't remember when I got it, but it has been a long time, 4 years or longer. It is the one I use for the church printing and I use it a few times a month. The other is an HP PSC 1510xi that I got in 2006. I sue it frequently,but not heavily, for personal use. The Lexmark I never have to turn on or off. It automatically turns on when I click on print, and turns off when the computer turns off. The HP I have to actually push the button on the printer to turn it on and off, but I can't tell that it goes into sleep mode. The lights never dim. Anyway it sounds like I don't need to worry about it when I forget to turn it off. I think I just got a bad cartridge last time, because they usually last quite a bit longer.
Thanks again

I'm not sure about Lexmark, but if you get a bad HP cartridge, they (HP Support) will lead you through some diagnostic tests and send you a free cartridge.