There's also the question of how do you want to border the print...

...some think borders don't matter since you can always frame with suitable bordering later - but I believe the frame + matt should be a bridge between the picture and the space it hangs so the Matt + Framing is decided later when the picture is hung; you still need to think about bordering.

Often of course you don't border the print at all if you are using a Matt in the frame - but you might, and you can, add borders.

The borders need not be equal all around so this might mean a very different shape of paper to shape of image.

I pretty much find printing on larger paper gives plenty of options for bordering and selecting image size.

I'm not sure how many people will agree with me here!! But the placement of the image on the paper is, I think, really important...

If you're interested take a look at: Article on Image Bordering