I am not sure if this is the proper place for this but is my best guess. When a deck is used up to throw it away is a wast of resources used to make it. When I use them up if I am not giving them or selling them off to freinds. I use them for gimmicks, throwing, and backpalming. Or any use the doesn't require a slick deck. I don't but as Ricky Jay stated in his book Cards As Weapons you may string them into a decrative cant think of the word but you get the idea. Or I suppose you could make a collage of different cards. Like a printout with out spending hundreds of dollars on ellusionst. Anyone have any other uses for old decks?

Put all your mismatched cards together in an empty card box, and you have your "Card Warp", etc. deck.

Bob Phillips

Practice your mercury fold?

Good idea

See 'The Cardwarp Deck', Darwin Ortiz 'At The Card Table' book.