PRODUCT DESCRIPTION The everyday tank made for the long haul * 100% SUPIMA COTTON * SQUARE NECKLINE Know what your wearing Not all cottons are created equal. Supima cotton is a superior type of cotton grown in the USA. It represents less than 1% of cotton grown in the world. What makes Supima unique to other cottons is the extra-long staple fiber that gives the cotton its premium properties: Strength, Softness and Color retention. Not all cottons are created equal. Supima cotton is a superior type of cotton grown in the USA. It represents less than 1% of cotton grown in the world. What makes Supima unique to other cottons is the extra-long staple fiber that gives the cotton its premium properties: Strength, Softness and Color retention.