When mounting a print it is important to visually isolate the print, placing the print in the centre of a mount creates an optical illusion that the print is not equally spaced at the top and bottom.  To overcome this illusion many photographers / framers adopt the technique which invovles placing the print at the Optical Centre.

Below is a link to help you locate this optical centre, the website allows you to enter your photo and matt sizes.

http://www.russellcottrell.com/photo/centeringHTML.htm

For your inner math geek, there formula is explained.

http://www.russellcottrell.com/photo/centering.htm

Obviously mounting of images can also be based on your personal preferences but we suggest you give it a go and see if you think it improves the display of your photos.

Thanks to Ben Knight for sending us this link.