When evaluating cotton waste yarn, focus on the composition ratio (e.g., 70% cotton / 30% polyester), yarn count (typically ranging from Ne 0.5s to Ne 20s), and breaking strength. For industrial applications like mops or cleaning cloths, a higher twist per inch (TPI) is essential to prevent shedding, while for weaving blankets, a softer feel and consistent thickness are prioritized. Always request a fiber length analysis to ensure the waste material is long enough to maintain structural integrity.