Okay, if anyone else is considering this (and Jack, for you as feedback), the cards cannot be given to a printer as they are, because there's no margins (either in addition to the card format or an inner margin). The way they are, printers cannot cut them with precision.
Additionally, backs and fronts are not in separate files, which printers hate.
To create the correct files, you need to:
a) Print a PDF from Cards.pdf with this pages option for all the backs:
1,1,1,1,1,1,1,1,1,1,1,1,1,1,16,16,16,16,16,16,16,16,16,16,16,16,16,16,31,31,31,31,31,31,31,31,31,31,31,31,31,31,46,46,46,46,46,46,46,46,46,46,46,46,46,46,61
b) Print a PDF from Cards.pdf with all the front sides:
2-15,17-30,32-45,47-60,62
Now you have 2 PDFs, which your printer company will like! Alas, they have no margins. Maybe you can order cards that are a little bit smaller (say, 64 x 114, cutting 3mm off each side), that would be easiest. There's no text near the borders, you'll only lose the colored border. Jack, if you included these files and erased the colored border, people could more easily give it to printers!
If y'all have access to something like GIMP, you could open the PDF and color in the border in the color of the background (which I will do).
I'm looking forward to playing this soon! :) My printer takes 17€ per card set.