"Music That Glows In The Dark"
If they are just proxies then 110 lb card stock makes a decent card, but you'll have a hard time matching the color and finish. If they are just proxies and are not being shuffled, then it's good enough. Or at very least, a ream of card stock isn't that expensive and it'll still be useful for other things.
Is there a particular brightness I should search for that will match better?