Insultex is not the costliest component of an IX UQ, but it has the largest minimum order cost of any component.
The board of directors of Molly Mac Gear have asked me to investigate replacing IX (Insultex) with 1/32" PE (polyethylene foam). Insultex is polyethylene foam quilted inside a polypropylene scrim. Plain PE foam, like Insultex, is only available in large rolls (670 yards), but costs far less, and can be purchased locally without paying shipping costs. I will not use PE foam without a nylon cover, because it is not quilted or faced. A prototype Baby Orca PEF UQ will be completed this week.
What got me interested in PE is a comment from Ed Speer last spring. He said, if PE based Insultex is essentially a vapor barrier, why not use PE foam instead, since it is much less expensive?
Ed, we're going to give it a try!