What to do with unmarketable cards?

Maybe someone else is missing them and can craft a badge? Or are they untradeable too?

edit: Oh, I found 7 cards in my inventory so far that are unmarketable.
edit2: Probably more, a page that keeps track:
https://steam-tracker.com/apps/banned
edit3: or just use the inventory search filter in steam, lol, 112 items unmarketable in my inventory

You can trade them away or trade to get the others.
It's gonna require a dose of good luck.

I just "gem" them, but I imagine they must have some worth if you can't purchase them anymore.
Perhaps one of those card-trading groups would be an option.

There are traders usually that buy them for gems. I suppose that's the best option. I even got an unmarketable booster pack drop today. I didn't know that's possible. xD

if you have more cards , the equivalent rate I can give a game in

You do not have a game in exchange for a card on the value of the game can you give ?

http://steamcommunity.com/groups/CleanUpYourInventory

You can trade them away against other cards or against a few gems.

I take often such cards when the deal is fair and i don't have that badge(s)

make and alt and dump them there

View attached image.

I traded mine in here in exchange for ~10 cheap sets. Not sure how good/bad the deal is but it was relatively easy/quick compared to other options.