I designed an UL WPB modified poncho that is also fairly durable. It’s blows everything I’ve ever previously tried, out of the water. I still bring a highly water resistant wind jacket, and so arms are not a big issue if it’s raining super heavy and/or cold.
I’ve tried regular non permeable ponchos (silnylon and cuben) and while they are decent, I still often found my chest area over sweaty and hot. Not so with the version I came up with.
It’s a combination of a UL silnylon fabric that wasn’t very water proof to begin with and which I ran under my sewing machine non threaded while the fabric was folded. Sewed to that is “kite” tyvek (1443R type), but only on the top and sides–the bottom piece of tyvek is a bit shorter and not flush with the silnylon. That’s too allow any excess rain that might get through the silnylon layer to drain down and out.
No hood. I took a wide brimmed hat, and sewed soft velcro to 4 areas. Took a highly water resistant, but slightly air permeable fabric and cut to shape and sewed corresponding velcro to that. It’s a regular hat when I want/need it, and it’s a WPB hat when I need it.
I even modified a pair of mostly nylon (with a touch of cotton) shorts to go along with it. Sewed some soft velcro to the bottom edge and quickly sewed up some matching pant legs made out of EPIC fabric to go with them.
Entire system is pretty light weight and more important to me–highly adaptable. Wore it on a CT hike.
Btw, when it’s particularly wet and nasty, I recommend wearing a fishnet type baselayer or Cap 4 type baselayer in combo with any rain wear system. It helps you from feeling as chilled. You can still wear a more regular baselayer OVER that, and/or a windjacket in combo, but the fishnet or Cap 4 really helps when it’s really wet, cold, and/or intense.
It’s easy and cheap to make your own fishnet system btw, and more comfortable than a lot of the other ones. Get some of that super bulky, chunky yarn–the real thick stuff. Get some of the iron on non sew stuff (the good quality stuff that bonds strongly), take a slightly over sized, thin, breathable, wicking shirt, turn it inside out and bond that thick yarn on so that it keeps the shirt fabric away from your skin and maintains some constant air space in most areas (especially your core). Voila, cheap, easy, comfortable “fishnet” type baselayer.
I tried this once with polypropylene cord/rope, and while it technically worked, it’s not nearly as comfortable as using thick yarn. It was also overly stiff.
I like the yarns that are primarily synthetic (usually acrylic), but have like 20% to 30% wool. These are less stinky than non treated polyester shirts for example. There’s just enough wool to cut down on odor some, and not enough for the over saturation issue of wool to be an issue (and even if the wool content gets a little soggy, you’re primarily dealing with air space in such a system).