What is Muestra (turned-up card)?

The muestra is the card turned face up after dealing that shows which suit is trump.

In Guiñote and Brisca it stays under the stock, visible to everyone, and is taken by whoever draws the last card.

In Guiñote, a player holding the seven of trumps may swap it for the muestra after winning a trick; in other games and regions the swap card varies.