“Go for a short walk, and you’ll know if your gear fits. You might notice the stretch, the lightness, the breathability, the warmth. But you won’t really know if it can keep you alive.”
The article/post linked to above is worth reading, not for the hyperbolic and jingoistic aspects of its marketing slant, but because it hammers home an essential truth of dressing for the woods: under duress the most important characteristic of your clothing system is not the ability to keep external moisture off you, but the ability to allow internal moisture to escape efficiently without chilling you excessively.
This is accomplished via several different tactics. Having base and insulation layers which respond to thermal pressure and move water quickly is one. Having enough shell gear, but not too much (i.e. wind gear rather than WPB if it isn’t raining) is another. The most effective and important, by far, is having pieces which hold the smallest amount of moisture possible.
My upper body system for the 2011 Classic was a Capilene 1 stretch tshirt, Capilene 2 longsleeve, hi loft fleece hoody, and a Goretex anorak. The tshirt was a poor choice, with a relatively high spandex content, and was consistently hard to dry all trip. A cap 2 tshirt would have made all the difference. My lower body system consisted of a pair of cap 2 undies, Patagonia Traverse pants, and Montane windpants. The windpants let my legs get soaked, so I brought real rain pants the next year, and while the Traverse pants dried fairly fast, they were still the weak link, and were replaced the next year with a pair of more fragile but lighter and faster drying 100% nylon supplex pants. For serious conditions little details like 4% versus 0% spandex content are absolutely worth sweating. It’s ironic that Sitka, of all companies, published this, as they are more guilty than most of excessive spandex use. The previous generation of the Traverse zip-t, for example, was without question the worst midlayer I’ve ever used due to an outsized ability to hold tight to sweat and water.
As a textile spandex doesn’t hold on to moisture, but in almost all occasions it is turned into a garment whose structure is a big island of moisture, and avoiding lycra/spandex is thus a good first rule for eliminating islands of moisture. That said, fabric thickness correlates more directly with drying time than any other metric; the thinner the fabric, the faster it dries. This is why the new lightweight Capilene (80 grams/meter!) is so exciting, and why the Alpine Start hoody is the best softshell fabric around. Pants remain a tricky one, as they often need to be a bit heavier for durabiity’s sake. Go as thin, tight-woven, and light as possible. Hats are another tricky issue, but Arc’teryx figured that one out a while ago. Insulating hats should be on the thin side, numerous, and able to layer over each other without causing eye-bugage. And so forth. These principles apply, with some modification, to items like backpacks and shelters.
It’s easy to dismiss concerns like these as only applying to a small percentage of users in eccentric circumstances, and while it is true that the extreme wetness which comes with packrafting did more than anything to open this issue up for me, it is equally true that if you spend enough time far enough from the car you’ll get bitten by islands of moisture. It can even happen during warm months in the desert, though such equipment and body stress is far less probable.
An investment in these clothing and equipment details pays dividends in comfort most of the time, and in a lighter pack which contains a larger margin for error most of the time. Occasionally, having already minded these things will make it much easier for you to save your own life. Not as sexy as “survival” stuff like firestarters and knives, but far more significant.