THE SWITCH (Gimmicks and Online Instructions) by Shin Lim
Imagine placing a Mystery card on a table, in someone's hand, in a clear
box, well... anywhere. This is done in full view of the audience. You
then have a another spectator select a random card and sign it. On your
command you cause their signed card to vanish completely from the deck.
The spectator is asked to open her hands, the mystery card that the
spectators has been holding the entire time is opened. It is the signed
selection!
THE SWITCH is the cleanest way to switch a card because there are no
boxes, no envelopes, etc. Words cannot describe how clean the switch
actually is.
You have to see it to believe it...