Just print it full frame and you'll have a white boarder around it. You could even add a black rectangle around it to mimick what allot of the documentary guys used to do to (larger neg carriers to show the actual edges of the neg) . I think it looks great. So what theres a white boarder its better than cropping or distorting the image.
This is a great solution, I rarely use standard sizes for my compositions, and thus make the "fix" with the Matting,. using actual mat board..
You suggest that one can use the option you outline to achieve the same thing when you don't want to make a custom mat... good idea.
Still, it loosk like it could use a crop off top and bottom to me in this case.


