So I'm working on making some cards -- playing cards, for a mini-game that I will be running during a session of Dungeons and Dragons. I designed the cards, got them printed out on a nice 350 gsm silk matte cardstock, and bought a Sizzix Foldaway die cutting machine for cutting them out using an artist/trading card (ATC) die.

The front of the cards turned out just fine. Here's one:

A non-player character card. Looks great!

But unfortunately, the same cannot be said of the back of the cards. Here's the back of the same card:

The back of the card, all chewed up by the cutting process.

As I worked, the lower cutting pad quickly accumulated lines from where the die pressed into it on each pass, which then got embossed into the back of the card. Which is ugly.

Disregard the white line -- the problem there is that somehow during the printing process all of the images on the back side of the sheets got shifted up by 3 mm. Probably because the cardstock was too thick to duplex automatically and had to be flipped by hand. I'll work on that for the next revision.

What can I do about the embossed lines? Is there some alternate sort of cutting pad I could use? Or some way to protect the card, maybe with a second layer of card stock underneath? This is literally the first time I've ever used a die-cutting machine, and I'd like to figure this out, because I'm pretty unlikely to use it for anything other than cutting out playing and game cards of one sort or another.

I'm sorry this is not specifically a greeting card, but I'm hoping this community will have people familiar with the tool in question even though the project is slightly off topic.