Check (pattern)

Check (also checker, Brit: chequer, or dicing) is a pattern of modified stripes consisting of crossed horizontal and vertical lines which form squares. The pattern typically contains two colours where a single checker (that is a single square within the check pattern) is surrounded on all four sides by a checker of a different colour. The pattern is commonly placed onto garments and is, in certain social contexts, applied to clothing which is worn to signify cultural or political affiliations. Such is the case with check in ska and on the keffiyeh. The pattern's all-pervasiveness and simple layout has lent to its practical usage in scientific experimentation and observation, optometry, technology (hardware and software), and as a symbol for responders to associate meaning with. The word is derived from the ancient Persian word shah which means "king" in the Sasanian game of Shatranj; an old form of chess which is played on a squared board of alternating coloured checkers. It is more specifically derived from the expression shah mat, "the king is dead", which in modern chess parlance is referred to "check-mate". The word entered the French language as echec in the eleventh century, thence into English. The incorporation of the checkerboard pattern in man-made objects has no definitive origin as the pattern has existed in assorted forms with multiple variations across continents and time periods. There are few known instances of its import into the regions and cultures in which it is featured. Its design and incorporation by humans into pattern-making and weaving precedes its common etymological characterisation and derivation from the word shah in chess; the language conventions from which the contemporary English word 'check' is extracted are younger than some appearances of the pattern or its variations. Human uses for check predate its notable usage on the checkerboard in the board game chess, which was developed in its chaturanga iteration in the late 6th or early 7th century AD.