Tree-fibre. New, innovative, bio-degradable and less harsh on our planet. We use it as the engine for our duvets. It makes for the most moisture wicking, sweat beating duvet that the UK has seen and experienced. It is also, unlike bamboo fully tumble dry compatible and becomes softer after every wash. It is an all-round , all-season duvet suitable for people looking to upgrade their sleep to more natural and greater products.