After twisting the tie back around, you ask the spectator to select a card from your deck. The card is then held faced down against the back of the tie. In the first climax, you mime peeling the card off, to show that the face of the card is now revealed on the tie - it's the card that they picked!
As an incredible kicker, the card they picked is turned over to show that the middle of the card is blank, but the numbers above the pips remain— it's as though you wiped the ink onto the tie and created a transfer! The card and tie are now fully examinable!