In my book, "See Mark Paint," I devote most of a page to "Ethical printing" because I think it is very important. Basically, put yourself in the position of the file creator, how you would feel if someone took your CCA (Creative Commons) non-commerical licensed file and started printing and selling it. It's bad juju, Karmic debt, whatever you want to call it.
This is why I stress ethical printing. If you don't, lawyers get involved and they are expensive.