Awhile back, I bought my spouse a thinnish, cable knit sweater at Uniqlo that has some cashmere in it.
The specific blend is 37% polyester, 19% acrylic, 17% nylon, 17% sheeps wool, and 10% cashmere.
Being a bit of a fabric/materials geek, and except for it being low cut at the neck line, it’s fairly gender neutral looking, so I’ve worn it to see how it would do as far as stink and warmth. Â It apparently has enough combined nylon, sheeps wool, and cashmere, to help reduce odor significantly below a 100% non treated polyester garment.
It’s also fairly warm for the weight, but I would have no idea how to quantify that with any accuracy. Â All in all, I would say it would make an excellent mid layer for more extreme cold (especially if it had a higher neck!) and has enough synthetic fiber ratio, to make it much more durable over a full cashmere or sheep’s wool piece and to speed up drying time a bit.
But where Cap 4/Thermal weight grid fleece shines, is that it’s a bit like wearning fishnet. Â Fish net and Cap 4 fabrics, I’ve found, are the most comfortable base layers when its either very cold and very dry, or cool and sustained wet. Keeping that primary air space next to the skin is key. Â Wet fabric, whatever it is, loses a lot of insulation and becomes much more conductive because the air space in the fibers is taken up by water, and water itself is quite conductive.
Fishnet and Cap 4 keep a constant layer of air directly next to your skin, and it’s definitely more comfortable in extreme conditions.
If I was ever to do a Tough Mudder type competition (especially if in winter), I would wear a PP fishnet baselayer, with an inverted Cap 4 baselayer over that, and a thin, UL windjacket over that.