When sourcing Cotton Single Jersey, the primary technical indicator is GSM (Grams per Square Meter), which typically ranges from 140g to 220g for standard apparel. You must verify the yarn count (e.g., 30s, 40s); a higher number indicates a finer, smoother thread. Additionally, check the composition percentage—while 100% cotton is breathable, adding 5% Spandex/Elastane significantly improves shape retention and elasticity. Ensure the fabric has undergone combed cotton processing to remove short fibers, resulting in a higher-quality surface with less pilling.