The specs on this thing are insane - no other way to put it.
It has 300g (10.58oz) of 850fp polish goose down
Total weight 480g (16.9 oz)... and that includes the weight of the stuff sack!
So that makes the weight of the fabric probably around 150 grams (5 oz) - wowzer!
The fabric is the super awesome Toray Airtastic.
Check out this bag on the Malachowski website!