Can FinePrint scale one paper size to another?

Yes. Suppose you want to print an 11×17 document on letter size paper or print an A3 document on A4 paper. In your application, set the paper size to the original (11×17 or A3 in this case). When the FinePrint dialog appears, select the Properties item in the printer list on the toolbar.  Set the paper size to the new size (letter or A4 in this case). FinePrint will rescale to the new paper size.