I wasn't quite sure where to post this so if anyone has a better suggestion let me know...

I recently came across a video of a live David Copperfield Show from 1998. In it he performs an effect with a piece of paper with many different symbols on it front and back. Spectators are asked to fold the paper anyway they want until only one symbol is visible then tear off the border of their folded packet so they are left with a stack of symbols. They then sandwich the stack between their hands and after some by play by Copperfield, all the symbols have changed to images of hands. There were about 10-15 people around the audience participating and they all ended up with nothing but hand symbols.

Soooo, has anyone ever seen this or know any kind of history of this effect? Copperfield never performed this on TV. This was only done in his live show.

Any info on this interesting effect would be appreciated.