I was hoping they'd go into how the got the cards actually printed?

According to the store page, the cards were printed and bound in China. There are a lot of different card manufacturers there.

For very small runs of 1-10 decks, I've used places like makeplayingcards.com. The cards are print-on-demand quality, but far better than printing at home on cardstock. (My preferred home printing method for prototyping is to use custom labels and cheap Magic the Gathering bulk commons.)

We did a card game that was printed by Panda Game Manufacturing in China. Since we did about 5k units, they used traditional offset printing on 300gsm blackcore (similar stock to Magic the Gathering). But the minimum order quantity is 500 or 1000 units. Costs per deck were vastly cheaper than the print-on-demand decks.

There is a company in Florida called ShuffledInk that will do custom cards. I've used them for a 50 deck order. Cards were more expensive, but did save a little on shipping. It took a couple months longer than printing in China, but the print-on-demand card quality was higher.

For all of these printing methods, preparation was the same. Design the cards in Illustrator, and follow the printers directions to prepare the individual files (PDF or PNG, depending on the service). MPC has a tool that you use to upload the images and layout the deck. Panda and ShuffledInk take the PDFs or Illustrator files for layout, then send you a digital proof to approve.