Tencel. This is actually the brand name for a type of material made from lyocell which is derived from wood pulp or bamboo and is produced through a closed loop process to minimise toxic waste. Tencel requires less energy and water to produce than cotton, and one producer called Lenzing AG are now using renewable energy sources to minimise their impact. It’s also 50% more absorbent than your average cotton tee making it ideal for activewear!