What is core-spun yarn? What is the purpose of core-spun yarn?
"Core-spun yarn is generally made of synthetic fiber filament with good strength and elasticity, and short fibers such as cotton, wool and viscose fiber are twisted together. Core-spun yarn has the excellent properties of filament yarn and staple fiber. The more common core-spun yarn is terylene cotton core-spun yarn, which uses polyester filament as the core yarn and outsources cotton fiber. There is also spandex core-spun yarn, which is made of spandex filament yarn and other fibers. A knitted or jeans fabric made from this core-spun yarn can stretch and fit comfortably."