yarn

Thread produced by drawing and twisting together fibres or filaments.

There are two main categories of yarn: single, continuous filament yarn and spun yarn. Continuous filament yarn is made when two or more filaments are drawn and twisted together (which stretches the filament slightly). Synthetic fibre is initially produced as single filaments. Silk is the only naturally-occurring single filament fibre. Spun yarn is made from shorter (or staple) fibres. These include all natural fibres except silk, but may also include synthetic filaments which have been cut to form staple fibres. Staple fibres are made into a yarn by combing (to straighten the fibres), drawing, and twisting (spinning). Staple yarns tend to be bulkier, softer, and less lustrous than continuous filament yarns, which are usually used for smooth, shiny fabrics. However, continuous filament yarns can be given different textures, by different texturing and bulking processes.