Eiderdown is one of the warmest natural fibres on the planet, both light and highly insulating. It is used to make some of the world's best duvets and quilts.
The eider is a sea duck from the subarctic oceans and the eiderdown comes from these ducks.
Iceland is the world's largest producer of eiderdown. The handpicked down sells for thousands of euros a kilo, catering to those looking for exclusive products.