I use a mount called Munken Lynx and I use a double mount for a refined finish. If your framer doesn't have Munken Lynx, I suggest a smooth mount very similar in tonality but not brighter than the actual paper itself.
The window / opening of the mount is typically 2.5cm (1") wider than the print (1.25cm each side). This gives space to the print and signature/title.
I emboss every print close to the edge so that it can be seen just above the mount. This is very subtle and not noticeable unless you are looking for it.
All prints should be rolled in the opposite way to the natural roll in the paper before mounting / hanging. I suggest using acid free tape on the top of the print only and let it hang naturally behind the mount.
I use a classic black wood frame, the depth for most sizes is 44mm and the width at the front is 20mm for a clean look.
Dimensions of Frames
Please note, all dimensions are in cms except for moulding / frame which is in mm