Cotton yarn is manufactured through processing the fibers extracted from the cotton plant, which is cropped where warm and humid climates run. Fiber lenghts are usually between 15-50 mm. In order to improve tenacity, cotton fibers are treated with sodium hydroxide; this process is called mercerization. Cotton yarns fall under three categories based on fiber specifications; carded, combed, and vigoine (vigoine is made of fibers leftover from carded and combed systems). In terms of the creation of the yarn, both ring and open end spinning systems are applicable.