A signed card is torn into four equal pieces. The pieces are then magically reassembled until the original card is whole once again.
This effect requires little explanation, in that it is really a simple matter. Before the effect is performed, the magician obtains a couple pieces of clear tape and puts them somewhere handy, such as hanging off the back of the magician's belt. After the card is torn, the magician just tapes it back together again, using magical gestures and patter to cover the rather mundane procedure.
If the card is going to be handed out after the effect for inspection, Scotch brand invisible tape is used.