How to do it:
To print on a paper bag, invert the image (across horizon) — that’s landscape, I think.
Click on “Custom” and enter the dimensions (5.2×10.2).
Rename the custom print, “paper bag”.
Hit OK and you’re all set. Next time, you’ll just have to go to paper size and select “paper bag”.
I’m going to try this out today. I have an EXCELLENT Tangled party idea. I’ll let you know if it works…