Yarns vary in their complexity. Some appear quite simplistic while others seem far more complex. There are varying degrees of complexity in yarns and various means of achieving the complexity.
The basic yarns that appear very regular and uniform are known as simple yarns. A variety of other yarns that are not so regular or uniform are more complex and are referred to as fancy, novelty or complex yarns. Fancy yarns may use any number of three basic components: the base yarn, effect yarn, and binder. The base yarn provides the support for the yarn structure; the effect yarn creates the decorative appearance of the yarn; and the binder yarn helps to secure the effect yarn, providing additional support and maintaining the desired appearance.