Double Covered Yarn

Spandex Yarn is first covered with Polyester or Nylon DTY in a spiral wave with S twist & then on top of it, the yarn is again covered with Polyester or Nylon DTY in a spiral wave with Z twist. One is outer covering, and the other is inner covering. Spandex is double covered with yarn and final yarn has zero torque. The different TPM and DR make various senses of comfort touch and extension.