Sea To Summit's premium silk travelling sheets are made from the finest ripstop silk with added Polyester/Lycra stretch panels along the length of the seams. These stretch panels allow the liner to move with you when you turn, roll and curl up in the night. FEATURES Premium AA Grade, ripstop silk. Polyester/Lycra stretch gussets improve comfort and life of liner. Increases thermal performance of sleeping bags. Machine washable and Colourfast. Lightweight, super compact. Double folded and reinforced seams. Extends life of sleeping bags by keeping them clean.