Tartan is a pattern consisting of criss-crossed horizontal and vertical bands in multiple colours. Tartans originated in woven cloth, now used in many other materials. Tartan is particularly associated with Scotland. Scottish kilts almost always have tartan patterns. (Tartan is also known as plaid in North America, but in Scotland, a plaid is a tartan cloth slung over the shoulder or a blanket.)
A Tartan is made with alternating bands of coloured (pre-dyed) threads woven as both warp and weft at right angles to each other. The weft is woven in a simple twill, two over - two under the warp, advancing one thread each pass. This forms visible diagonal lines where different colours cross, which give the appearance of new colours blended from the original ones. The resulting blocks of colour repeat vertically and horizontally in a distinctive pattern of squares and lines known as a sett.
Until the middle of the nineteenth century, the highland tartans were associated with regions or districts, rather than by any specific clan. This was due to the fact that tartan designs were produced by local weavers for local tastes and would tend to make use of the natural dyes available in that area.