Just read all the answers, great bunch of thoughts. Just to add one more, or restate what others have said: When I make a print (presumably for others to see), I believe that I am trying to share, explain, show - an experience I had, when shooting, processing, evolving an image. There's an essence there in the image, for me, and the print is the way I have to communicate it. Should it be a big print, or a small one? All of the other factors may be present in that final feeling, but maybe it's that simple.