Focus with package

Take any 12 cards, shuffle them. Ask any viewer to choose any card. Then take the package and put these cards into it. Ask any viewer to shake the package in order for the cards to mix well. After that, you lower your hand into the bag and get out the card that the viewer chose. The secret of the focus is that before taking the focus you take a piece of adhesive tape and paste it on the finger of your right hand. When the viewer selects the card and gives it to you, then you take the card in your hands and, without looking at it, keep the face to the spectators in such a way as to imperceptibly paste a piece of adhesive tape on it. The viewers should get the impression that you just want to hold the card in your hands before it is placed in the deck and put in a bag. In the package, you can easily find the card to the touch, after which you must separate the sticker before removing the card from the package. Hide the sticker between your fingers.