My Cotton merchandise is 100% organic and 100% responsibly sourced cotton. This ensures the highest quality of the clothing that makes them last longer than other merch you have bought. The non-cotton workout T-Shirts are made out of high quality functional fibers, making the shirts extremely light, breathable, and fast to dry ... ideal for intense training! The prints are the highest quality as well, while being washer & dryer safe (with delicate or low temperature program).