Quote Originally Posted by Mark Fisher View Post
... Ralph: in your diagram, how do you determine point "0" (or where line A is located)
The ‘optical center’ of the mount makes for an attractive print placement in most situations. To find this optical center, align the upper left-hand corners of the print and mount-board in point ‘A’. Now, bisect the remaining spaces to the bottom and right of the print, creating lines ‘a’ and ‘b’, respectively. Then, connect point ‘B’ and ‘0’, creating line ‘c’, which intersects line ‘b’ in point ‘1’. Finally, align the lower right-hand corner of the print (point ‘C’) with point ‘1’ on the mount-board. The print is now at the optical center of the mount.

If you feel this results in the print being too high or too low on the mount, slide it up or down until you have equal top and side borders, or find a more attractive distribution of space, but always maintain a vertical print offset.