Recently, I spoke with Running Feather about the specifications of Insultex. According to the manufacturer, it weighs 0.44 oz per yard. He asked me to weigh it, because his Insultex weighs more than that.
I have been making Jerry Chair inserts, which weigh 2.2 oz after they are cut, and 2.4 oz. after they are finished. It It occurred to me that you could use these inserts as standalone IX UQs. Even with two of them nested together, that's a super ultra light UQ at 4.8 oz! [That doesn't include the suspension.]
The Jerry Chair Inserts are 20 square feet. One linear yard from the 60" roll is 15 square feet. If you do the math, you come up with a weight of 1.65 oz for a piece of Insultex 36' x 60". That's a lot heavier than 0.44 oz per yard!
Running Feather thinks the manufacturer specifies the weight of Insultex without the scrim. That could be... turns out Insultex is heavier than 1.1 ripstop nylon!