As the name suggests, this is a sandwich effect.

The performer says he is going to use the 2 black Kings.  He spreads a deck of cards face upwards and shows that the 2 black Kings (the King of spades and the King of clubs) are far apart from one another.  They are separated by more than 2 dozen cards.

A spectator freely selects a card, but obviously not one of the black Kings.  This card is signed on the face.

The spectator cuts the deck and buries her card.  She then shuffles the cards.  The cards in the deck are spread face upwards.  Immediately the audience can see that her signed slected card is now between the 2 black Kings.  The 2 Kings and the spectator’s selected cards can be taken out of the deck and freely examined by the spectator.

So, what is the difference between this “Sovereign Sandwich” and other sandwich effects?  This sandwich effect uses a couple of gimmick cards.  Almost the entire effect is carried out by the spectator.  The 2 black Kings are initially shown far apart, the card is freely chosen, and the spectator cuts the deck and buries her card and then shuffles the deck.  Despite all these actions carried out by the spectator, her chosen card ends up between the 2 black Kings and the 3 cards in the sandwich can be examined.

You receive the gimmicked cards and a link to a video tutorial by David Jonathan.  There are 2 bonuses.  The second bonus allows you to show the 2 black Kings are still far apart from one another just before you cause the slected card to be sandwiched between them.  This will even fool the magicians.

The effect is easy to perform.  There are no critical angles to take care of during your peformance.  The sandwich occurs instantaneously, and the 3 cards can be fully examined.  (Rated 4.5/5 stars)