Kotatsu futon cover only ●Three-dimensional patterns created with fluffy pile The damask pattern is created using a technique called "carving," which involves cutting the long fibers of flannel fabric. The darker gray at the ends of the fibers is exposed, creating a textured pattern. - High density fabric The outer material is made of dense flannel. It is smooth to the touch and extremely warm. - Flannel lining The lining of the comforter is plain flannel fabric. Enjoy the warmth of a kotatsu while wrapped up in this fluffy comforter.