Spun yarns are long continuous length of interlocked fibers, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery, and rope making. Thread is a type of spun yarn intended for sewing by hand or machine. Spun yarns can be made from a number of natural or synthetic fibers. Cotton and polyester are the most commonly spun fibers in the world. Cotton is grown throughout the world, harvested, ginned, and prepared for yarn spinning. Polyester is extruded from polymers derived from natural gas and oil. Other commonly used synthetic fibers are nylon and acrylic. Animal fibers include wool and silk. Rayon fibers are produced from wood pulp.
Spun yarn is made by twisting staple fibers together to make a cohesive thread. Spun yarns may contain a single type of fibre, or be a blend of various types. Combining synthetic fibers with natural fibers is very common. The most widely used blends are cotton-polyester and wool-acrylic fibre blends. Blends of different natural fibers are common too. Yarn is selected for different textiles based on the characteristics of the fibers, such as warmth (wool), light weight (cotton or rayon), durability (nylon), or softness (cashmere).