Twist Per Inch - Variation Per Yarn

Variation Per Yarn

Twist is needed in yarn to hold the fibres together, and is added in both the spinning and plying processes. The amount of twist varies on the fibre, thickness of yarn, preparation of fibre, manner of spinning, and the desired result. Fine wool and silk generally use more twist than coarse wool, short staples more than long, thin more than thick, and short drawn more than long drawn.

The amount of twist in a yarn helps to define the style of yarn- a yarn with a lot of air such as a woollen yarn will have much less twist than a yarn with little air, like a worsted yarn. It also affects the stretchiness of the yarn, strength, the halo of the yarn, and many other attributes. Filling or weft yarns usually have fewer twists per inch because strength is not as important as with warp yarns, and highly twisted yarns are, in general, stronger. Warp yarns have to be stronger so that they can withstand the tension of the loom. Filament fibers, such as silk, or many synthetics, need only to be twisted slightly to create a yarn.