PSIMBOL Deck from Vernet Magic

You show forty white cards with different shapes printed on them, shuffle and place them face down on the table. You ask a spectator to cut off a small packet of the deck, look at the shape he cut and remember it. Next, ask him to shuffle the packet.  Then ask another spectator to take the balance of the deck from the table and place it in his pocket. All these actions are made with your back to both spectators.