History of Muay Thai. Muay Thai or Thai boxing is the cultural martial art of Thailand. The origin of Muay Thai dates back several hundred years, and was, essentially, developed as a form of close-combat that used the entire body as a weapon. Digitally Printed on soft superior 100% Cotton, Triblend, 50/50 premium Soft Style Quality T-shirts. Not Slim Fit Size XXL is Heavy Cotton. The Design Is Blended into the fabric of the shirt, No Peeling or Cracking High Quality Print. Quick Shipping By USPS First Class mail.