[Retronaut]

You can do it yourself. However, I would strongly advise against using it for portraits; it's really only meant for events and you are probably losing an awful lot of money involving it in portrait sales.

I see no need to bother with oddball sizes like 5X7, 8X10, 11X14 and 16X20 for professional portraiture unless it suits your particular image. At least you can get full-frame prints easily enough, including 4x6 which is cheap as chips and great for wedding boxfuls.