Tartan (Scottish Gaelic: breacan [ˈpɾʲɛxkən]) is a patterned cloth with crossing horizontal and vertical bands in multiple colours, forming simple or complex rectangular patterns. Tartans originated in woven wool, but are now made in other materials. Tartan is particularly associated with Scotland, and Scottish kilts almost always have tartan patterns.
Outside of Scotland, tartan is sometimes also known as "plaid" (particularly in North America); however, in Scotland, a plaid is a large piece of tartan cloth which can be worn several ways.
Traditional tartan is made with alternating bands of coloured (pre-dyed) threads woven in usually matching warp and weft in a simple 2/2 twill pattern. Up close, this pattern forms alternating short diagonal lines where different colours cross; from further back, it gives the appearance of new colours blended from the original ones. The resulting blocks of colour repeat vertically and horizontally in a distinctive pattern of rectangles and lines known as a sett.