Hello Rejean,
I searched our online knowledge base and could only find instructions on how to do mixed sized originals when copying nothing for printing. I would suggest calling into the support department @ 1-800-835-6100 to speak with an analyst to see if they have any suggestions for printing mixed sizes.
I have a customer who want to print a document that have letter and legal size in it, tray 1 is define has legal size and the bypass tray is letter and is not in bypass mode, autoselect is activate for both tray. When printing eveything go to the tray 1.
The customer use the 2 format regulary and also complaint that when printing legal size only document or letter he have each time to select the paper format in the driver, he find that annoying, is there a way to avoid that. Word and adobe reader are the software is using the most.