-Poker size (especially if not shuffled by people, but rather by a machine; even a cheap one).
-4 jumbo (or almost jumbo) indexes, 4- color.
-Index colors: Light red hearts, light blue diamonds, light green clubs (to not be confused with the spades' black at any time).
-Whatever texture is non-slippery (so on the "coarse" side)
-Bendable, elastic, durable and non-warpable (so acetate, like Modiano Platinum).
-Back colors: Either light blue and pink/fuchsia or light grey and yellow/gold. Or the majestic traditional designs of Fournier (FDL etc)