John A. White
Some companies that do print on demand prototyping will charge you extra, but when it comes down to the big print you will pay the same
Superior POD Does 18 per sheet and They do support unique backs... I'm not sure how to math 1a with 1b... to insure 1a is not stuck with 18b.
It is possible to find out and get it done right... you also have to address the orientation of the image.