Good morning;
Has anyone considered using a larger frame and a mat board to fill the space between the edges of the frame and the edges or borders of the print? You can cut the opening in the mat board to just about any format you need within the limits of the frame holding all of this.
In this way would it not be possible to retain the format of the original print size, say a 10 by 14 in a 16 by 20 frame, and in this way meet the desire of the customer, provide a servce, and make a nice profit also? That last point is the main thing that distinguishes a "professional" from an "amateur." I have seen many "amateurs" whose technical skills and their people skills did exceed those of some of the "professionals" I have met.