This routine starts like a classic one, but wait…
A blue back prediction card is placed inside an open envelope. It is visible to all the spectators from the beginning of the routine and will be never hidden.
In a deck of card with different backs (of your choice), ask the spectator to choose and sign a card and then lose it in the deck of cards.
What a surprise for spectators when they discover that the blue card VISIBLE SINCE THE START OF THE ROUTINE is the signed card!