Super Ink Fusion 

Stunning Card Effect Where The Signatures On Two Cards Jump Onto the Same Card

Effect : Two spectators each select and sign a card. One signature is signed on the face of a card and the other signature is placed on the back of the other card. Both cards are then placed face down on the table.

Then the spectator that signed the back of his card, holds it between his hands while the other spectator waves his card over his hands and when he looks, he sees that his signature has vanished from his card and when the other spectator looks at his card which he is holding in his hands, the other spectators signature has appeared on the face of this card. So both signatures appear on one card.??????

Preparation:  You will need a deck of cards and a duplicate card from another deck of the same brand.

Performance:  Put the duplicate card on top of the deck, followed by the other card i.e ( 6-clubs on top of the 6-clubs .)

Have a spectator pick any card and then force ( using your favourite force) another card on him. ( For this routine we will say the 6-clubs is the force card .) Replace the cards as follows from the top down: forced, selected, duplicate. 

Double lift to show the freely selected card and have him sign the face. Turn both cards face down and place the top card ( not the signed card ) on the table.

Double lift again to show the duplicate card. Then turn the double lift cards back down and have him sign the back, then place that card on the table.

Then place the card with the signature on the back, into the hands of the spectator that signed it originally.

Then, the other spectator picks up his card signed on the face and waves it over the card the other spectator is holding.

Now when he turns his card over, his signature has vanished from the face of the card.

Then, when the other spectator looks at his card, his signature is still on the back but when he turns it over, the other spectators signature has appeared on the face of his card.

Note: When you place the card in the spectators hand its a good idea to have him cover the card with his other hand. This stops the face being seen and makes the trick seem more impossible.