JAVA
Peter Eggink
Empty Hand Productions
For example: A card is selected by the spectator and a corner of that card is torn off for later verification. The card is placed back inside the pack - next you show your "Coffee to Go" cup and continue by springing all the cards towards the coffee cup... all cards drop on the floor except for one single card... one card - with its corner missing - is now actually trapped behind the cup sleeve and yes - it's the spectator's chosen card with matching corner.
The JAVA gimmick not only limited to cards: Use JAVA to make for example a bill, receipt, photo etc. appear, trapped behind the sleeve or even change a name written on the cup.
JAVA by Peter Eggink comes complete with cup sleeve, gimmicks and online tutorial. (Use your own paper coffee cups to complete the JAVA gimmick).