Tweed is a fabric used in making outerwear, such as jackets and trousers. It usually has a rough fibre of wool or raw silk and flecks of different colours blended within the yarn. Tweed is also flexible and fairly light in weight, though heavy enough to be warm. The word tweed probably came from the word twill, which is still a popular weaving pattern for tweed fabric. Today tweed is made in a wide variety of settings, from people's homes to automated factories.
Tweed is generally made from sheep's wool. The wool is sheared from the sheep, and then washed and dried. Harris tweed, a famous tweed from the Scottish Outer Hebrides region, was originally made only from blackface sheep. Now, tweed may be made from sheep's wool, silk or a blend of both. There are also tweed-style fabrics that blend wool with artificial fibres. The original use of wool in tweeds is what gave tweed it characteristic roughness, and this roughness is still maintained today, no matter what fibre is used. However, most tweed is still made from wool.
After the wool has been washed and dried, it must be dyed. Traditionally, some of the wool was left its natural colour, and some of it was hand-dyed using natural vegetable dyes. Lichen and blackberries are two possible sources for natural dyes for colouring wool intended for tweed. Some tweed wool is still hand-dyed, though this is rare, while other tweed wool is mill-dyed and still other tweed wool (the more inexpensive varieties) are machine-dyed. Natural and artificial dyes are used for dying tweed wool today, depending on the source of the tweed.
Blending is mixing these different dyed batches of wool together. Blending is an essential step in giving tweed its distinctive look. Because the yarn is spun after it is blended, each strand of yarn has variegated flecks of colour. Because of blending, from far away, the fabric may appear to be a neutral colour (if it is not obliquely patterned), but up close it will be subtle or colourful array of colour.
The wool is next carded and then spun into a rough, textured yarn. While traditionally done by hand and then milled, spinning is now done mechanically for some tweeds. The number of turns per inch, or the "twist" of the spinning, determines the look of the yarn--whether it is stronger or lighter, bulky or fine.
Finally, the tweed yarn is woven. It may use a simple weave pattern, creating a straightforward, plain weave, or a twill pattern, which creates diagonal lines. Other tweed weaves include the herringbone, hound's tooth, cheviot or plaid patterns. Harris tweed must be certified hand-woven on looms, while other tweeds are woven in factories just like other fabric.