<Tr> <Td> ​ 3 ⁄ </Td> <Td> ​ 2 ⁄ </Td> <Td> 88.9 </Td> <Td> 63.50 </Td> </Tr> <P> Modern playing cards are available in both "wide" and "narrow" sizes, often now commonly referred to as either' poker' or' bridge' sized; nominal dimensions are summarized in the adjacent table . Notwithstanding these generally accepted dimensions, there is no formal requirement for precise adherence and minor variations are produced by various manufacturers . </P> <P> The slightly narrower cards are more suitable for games such as bridge and some types of poker, where a number of cards must be held or concealed in a player's hand . In most USA casino poker games, plastic bridge (narrow) sized cards are used; this is for both ease of use and dealing, and the plastic cards last much longer than paper decks . Casino shuffling machines have traditionally been designed for "bridge" (narrow) size cards for these reasons . In other table games, such as 21 (blackjack), a modern casino may use hundreds or even thousands of decks per day, so paper cards are used for those, for economic reasons . "Poker" (wide) size paper decks are used for 21 and other similar games . Other sizes are also available, such as a smaller' patience' size (usually 1 ⁄ × 2 ⁄ inches (44 × 60 mm)) and larger' jumbo' ones for card tricks . </P> <P> The thickness and weight of modern playing cards is subject to numerous variables related to their purpose of use and associated material design for durability, stiffness, texture and appearance . </P>

What are the cards in a deck called