The selvedge denim is produced by shuttle loom. The weft is passed from warp in a back & forth motion. This results in smooth edges of selvedge. Whereas, a projectile loom manufactures non-selvedge denim, as it consists of only one thread of weft for each row. This results in more soft and delicate edges which are required to be sewn to prevent it from fraying. The ribbing of fabric in a diagonal pattern makes it different from cotton duck as well as canvas, which are strong materials similar to denim.