Wow, this actually confirms my thoughts about my Columbia Omni-Tech, that thing seems like the least breathable jacket I've ever owned. Good thing it has pit z

Wow, this actually confirms my thoughts about my Columbia Omni-Tech, that thing seems like the least breathable jacket I've ever owned. Good thing it has pit zips. It's like a cold rain jacket. There seems to be 2 distinct categories: some fabric is asymmetric when it comes to relative humidity, others stay constant (like Omni-Tech). The asymmetrics become more breathable as humidity increases. Schoeller WB-Formula starts off half as breathable as Omni-Tech at low humidity and at high humidity comes down to match. But you've also got Gore-Tex XCR, which is more breathable than O-T at even low humidity, and gets even more so as humidity increases. I've had a Columbia 3-in-1 with a softshell liner that I've really loved. It can take about ¼" of rain, but isn't quite as warm as a fleece. I washed the liner a bunch, but never washed the shell (still looks new, waterproof AFAIK). I just bought myself a Marmot 3-in-1 for Christmas (unaware of all this research). Shell is apparently Membrain, which is both more and less breathable than Omni-Tech (less when dry, more when humid). "Asymmetric" breathability fabrics, most->least breathable: Gore-Tex XCR, Entrant Dermizax, Gore-Tex, Membrain, Hydroseal, Sympatex, Conduit, Schoeller WB-Formula. All these are more breathable when humid (opposite probably not very useful). "Symmetric" breathability fabric, most->least breathable: Expanded PTFE, EVENT, Schoeller Dryskin Extreme, Entrant GII XT Laminate, Nextec, Lowe Alpine Triplepoint, Omni-Tech. The groups overlap, but symmetric fabrics are generally more breathable overall (especially when dry, but even still when humid). Interesting.