Breath Test
A stack of printed cards is shown, the face card depicts a breath-test kit. A spectator is invited to place his signature on the face, card of the stack. He is asked to breathe onto the breath-test kit picture, the card is removed from the stack and placed face down on the table. After allowing a few seconds for the result to develop, the spectator turns the card over and now written across the breath tester is the word SLOSHED. The card bears his signature. Very easy to perform, no moves of any kind.