And... to make matters worse the R value of a bag would change depending on how damp it was, or wet it was, the ambient humdity, because its absorbent, and prone to be used in a lots of different ways.
Same with lofting time, was it measured after being compressed for a week and allowed to loft for an hour, or allowed to loft for a week?
The variability would be phenomenal. Just as it is with "warmth" rating on bags now.
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