You are absolutely correct. Don't forget, even if you crop your images without maintaining aspect ratio you'll blow your "perfect" mat size anyway. *Most* of the photos I end up printing have had some cropping applied; usually. Sometimes. Maybe.
There are some in this forum which are either pro's or perfectionists and for them the image "is what it is" and they will print, mat, and frame (or bag) without regard to any standard sizes. That is fine. There is another group (of which I am one) which seeks to provide an economical approach as a compromise to perfect sizing.
Since I own a 17" printer (Epson 4880) I want to maximize my physical print size while trying to follow a few simple rules. I've standardized on two (with a bit of variation) particular sizes; a large size and a small size. For my large or maximum size I use 17" paper; either roll or cut sheets. These are for my very best prints. When I'm either testing or making my other size prints I either use a 10" roll or standard 8 1/2 x 11 pre-cut papers.
One of the rules I try to follow is to try to allow at least a 1 inch margin around the actual printed image (as suggested in "Camera to print"). This allows the print to be handled much easier without fear of touching the actual printed surface. So by following this rule, the largest size I would be printing (image size) is:
17 inch paper minus (1 inch on each border = 2 inches) = 15 inch. It pretty much works the same way for the smaller papers although sometimes I feel it is necessary to leave less than the 1 inch margin (sometimes as little as 1/2 inch on each side).
Since I know my maximum size for both my "large" and "small" prints, I can standardize on my frame sizes. I've chosen a 22 x 28 for my large prints and 11 x 14 for my smaller prints. This seems to work well enough for me. For my larger prints I double mat, and for the smaller ones I single mat.
Everyone has their own ideas, and mine is just my opinion which seems to work well enough for me.
Keep in mind I have not sold a single print......ever...... LOL. But I'm still entitled to my opinion! And I happen to think most of my prints have turned out pretty cool!
Todd in Chicago
I'm curious about this topic. On the Camera to Print tutorial, Michael says he uses a standard frame size, which is a great idea because one can order in bulk. However if the aspect ratio of the print doesn't match that of the frame, won't there be a difference between the top matte space and the sides? Shouldn't they be ideally made all the same space left = top = right with heavier bottom?