Down cluster. Photo credit: Wuzhen Down remains, arguably, the most efficient insulator available (although Aerogel with its amazing 95% air content, is trying), with which to make cold weather garments, sleeping bags and bedding, ). And according to the International Down and Feather Testing Laboratory (IDFL) “Down and feathers have the lowest carbon footprint of any other fill material, both natural and synthetic.” But high quality down is the plumage of ducks and … Read the full story on TreeHugger
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