I’ve never seen numbers on real furs - the only people who do numbers seem to be manufacturers of fabrics or garments promoting how wonderful their products are compared to other fabrics/garments and for some reason they don’t compare against furs - possibly because they would look bad? Fur sellers don’t do numbers presumably because they don’t need to. Also, numbers are not necessarily an indication of performance, and it’s easy to check whether a given garment is ACTUALLY warm. What do people exposed to extreme cold prefer to wear? Given that cold is life-threatening as well as uncomfortable, I’m happy to believe that fashion does not figure in their decision-making process.
The fur discussion seems to be debated by shrilling that it can never be justified because it’s so evil, etc. However anecdotal evidence from really cold places indicates furs are toasty warm, hence their popularity. My experiences match Hilarity’s - fur is REALLY warm. Others agree - from the Dutch National Museum of Ethnology in Leiden “The Inuit also buy modern polar clothing of this kind. Only in extremely cold areas, such as North Greenland, are fur garments still preferred, since they still appear to provide the greatest degree of insulation.”
Similarly, to quote from some random muntaineering page “By its very nature, a down-filled sleeping bag is as much as 35% lighter than its synthetic counterpart and is infinitely more compressible, providing the most warmth with the least bulk. Down is also known to have the greatest longevity and it will outlast any other insulation by three to five times, making it the most economical choice after its initial investment.”
Animal insulation is the result of millions of years of trial and error with nanoscale production we still can’t match - no surprise that it will outgun synthetics. Hence my assumption that any animal living in a really cold place will have the best insulation going. In fact penguins, leopard seals and whales are probably the best-insulated things on the planet, but blubber never really caught on as a clothing choice.
Hope this helps.
