Does Insultex have a moisture permeability direction?
This is not meant to be an absolute technical evualation of Insultex, simply an observation.
I marked my 10 yd. bolt of Insultex, one side "a" the other side "b", so as to be able to use the that Insultex material later with proper orientation. Then I cut two 10" squares of Insultex, and also marked the same side orientation as the bolt, 'a' and 'b'. Placing each 10" square on two seperate bowls, one with the 'a' side up, the other with the 'b' side up, the top surface was dimpled down enough to hold 4oz of water. Results are as follows:
After 1 hr.
Sample 'a' water had seeped thru, about 1/2 thimbles worth.
Sample 'b' dry
After 18 hr.
Sample 'a' only a few drops had not seeped thru.
Sample 'b' 1 oz had not seeped thru.
I suspect seepage of any kind could be slightly increased by the quilt thread stiching of "scrim-like" layers thru the closed cell layer. But, the manufacturer may have used thread which does not permit such seepage.
How to visually tell the difference on which side is which for permaebility, I have no idea, glad I marked it!
I'm only using Insultex as a layer in my down quilt at this point, after reading reviews, I'm not planning on using Insultex for clothes due to it's lack of breathability with any serious exertion, such as backpacking, yet, although a poncho would not present a problem. It's still a valuable material as far as I'm concerned, and I will have many uses for it.