If you have any picture framing or matting and mounting questions please feel free to ask them here since other APUG members might have the same question. I also try to place information on our website to help photographers with their framing and we have a few pages that you might find useful:
General Framing Info about mats, glass and acrylic, gallery style framing
Picture Mounting Techniques such as t-hinging, photo corners etc.
We also have a list of 80 different picture frame sizes here
If we dont have a size you need we also do full custom and have help here.