Invisible Card Punch by Dave Powell
With the Invisible Card Punch you will be able to achieve amazing card effects by making a small bump on any card. You can now mark cards before performing or secretly mark a card anytime you wish, right in front of the spectator's nose. By placing a small amount on the reusable adhesive Handitak also known as Funtak on the back of the gimmick, it will stick to your thumb or index finger. Now you can have a spectator freely pick a card and secretly mark the card with a bump by pressing on the front or back of the card depending on which trick you wish to perform. The spectator can shuffle the cards as much as they want and you can always find their card immediately (This is great for ambitious card routines.) I have included several routines but I'm sure you will discover many more uses for the Invisible Card Punch.