While the Phentex Harmen sent me is not twisted but parallel, the strands are wavy. I don't know how the strands stay together like yarn since they are not twisted or intertwined but it is NOT polypropelene. My "expert" opinion as a longtime supplier of Tyvek (spun olefin by DuPont), is that this Phentex sample is the real stuff (olefin fibers). I can't tear it, it's waterproof, you can't MAKE it sink in water, and it has the same feel to my fingers.
Murf
Is the Phentex that you got similar to Poly-Yarn? Is it twisted like
regular yarns, or are the fibers all parallel?
