oh - not a dumb question at all! i had no idea either! i honestly didn't end up using mine for much - just on here in my siggy, and on my OOT bags. what i did is basically just open the file, mine are .jpg, and print them on some transfer paper (bought anywhere, like Office Depot) - it's paper to iron on fabric - and then iron them on the bags. some people get a lot fancier, and use them all over teh place (invites, tags, etc.) but i didn't.