Researchers investigating the properties of cotton, polyester, and rayon binary and triple blended yarns assessed yarn tenacity, extension at break, work of rupture, irregularity, and coefficient of friction. The tenacity of triple blended yarns with a count of 20/1 was lower than that of binary blended yarns of the same count when the percentage of polyester was lower than 30. The tenacity of both binary and triple blended yarns with a count of 30/1 was equal when the polyester percentage exceeded 35. The tenacity of triple blended yarns with a count of 40/1 was higher than that of binary blended yarns when the polyester content exceeded 40 percent. An increase in yarn percentage improved yarn extension at break. Increasing the polyester or rayon percentage increased work of rupture. Yarn irregularity depended on polyester percentage. The coefficient of friction for triple blended yarns with a polyester percentage of up to 40 percent was higher than that of binary yarns. 19 refs.