SUMMARY: A weaving trial with a size-less cotton warp was conducted under mill-like conditions on a modern high-speed, flexible-rapier weaving machine. About 150 yards of a 1/2-twill fabric (64 epi and up to 56 ppi - face down) was produced up to 500 picks per minute without any warp yarn failure or breakage. This certainly is a very encouraging achievement, which at least demonstrates for the first time ever the "mechanical feasibility" of size-less weaving of 100% cotton yarns on a modern high-speed weaving machine. However, quality of the fabric produced is less than satisfactory, mainly because of the random formation of tiny unsightly fibrous balls on the fabric surface. The ball formation most likely is partly due to warp yarn abrasion (yarn-against-yarn and yarn-against-weaving machinery components) and partly due to warp yarn disintegration caused by some loss of twist due to repeated yarn extensions and relaxations that cyclically occur at high frequency during weaving. Multi-prong efforts are continuing to eliminate the fabric defects. Description of the weaving trial, weaving performance, and fabric quality will be discussed in a presentation at the 2006 Beltwide Cotton Conferences.