The BFF fabric is named as it might just become your best friend forever. The flats are made from 320gsm, have a slight 4-way stretch fleece, and contain 67% bamboo, 28% organic cotton, and 5% lycra (spandex) and are serged with textured polyester thread. The stretch is 50% in one direction and approximately 15% in the other direction. They are smooth as a cute little babies butt on one side and fleecy on the other. The fleece can be worn against the skin or facing outwards. They are super absorbent, pin and snappie great, and stretchy.