I used to live in Florida, where the summers would get very hot and humid, and my cards were warping like crazy! So, I was talking to other magicians online about this problem, and most recommended a "porper clip."
So, I purchased this clip, and when it arrived, I put a warped deck in it, and within a few hours, the warp was gone, and the deck fanned, cut, and handled like NEW!
I understand that there are many other card clip's in the business, but the Porper card clip is simply the best of its kind. The curved spine allows pressure to be added all over the cards, so each card is being pressed down and kept in perfect condition. (Other clips may not have this spine, and may not even be tight enough, therefore, not adding pressure, and not even helping your cards! - the Porper clip on the other hand, never wears out or gets wider, and keeps an equal amount of pressure on all the cards, ALL THE TIME!)
Even though the Porper Clip is $22.50 (PenguinMagic is definitely the CHEAPEST place you can buy this amazing clip, other sites like E sell it for $32 + shipping!), you get your money back by buying less decks of cards, plus, the Clip looks very professional and beautiful - midnight black (and it is very hard to get any scratches on this clip) with Mr. Joe Porper's signature engraved on the spine of the clip.
10/10 without a doubt.
If you are a serious card worker, you need this!
Strongly recommended. Plus, your cards will thank you for saving/extending their lives!