Soft & Comfortable Short Sleeve Classic Relax Fit T-shirt for Men & Women. 70% viscose from Bamboo and 30% organic combed ring-spun brushed Cotton. The term "viscose" refers to a regenerated cellulose fiber obtained through the viscose process. Good news: bamboo viscose is breathable! In fact, it has excellent moisture-wicking properties, releasing moisture and heat from the body while still providing a barrier from the outside environment.