Best Base Layer?

Hands down Merino Wool. No synthetic has the same thermal range properties as Merino. I like Ice Breaker clothing as well as Smart Wool. Ive worked (and played) in the outdoor industry for nearly 20 yrs and have never found a synthetic piece that could be worn for more than a day without smelling. While trekking in Nepal a few yrs back, I wore the same Merino piece for 3 week and I kid you not, it did not smell. You can even wear your merino to a smokey bar. It will smell when you get home but give it a few hours and the smell will go away. Try doing that with petrol based synthetics! Youll pay more but in theory youll need 75% less garments for the same trip. The Merino also keeps you cooler in warm weather and warmer in cold weather. Its like the thermos of textiles!

I think the best base layer is silk, especially for it's heat holding to weight ratio. I have silk longjohn shirts and pants that I use when backpacking in the Sierra's and they feel great against your skin, provide a nice heat layer, aren't bulky under pants or jeans, and weight almost nothing.

silk weight Merino wool or silk weight advanced wicking clothing. Always silk weight. If doing backcountry style xc skiing, it is always best to be able to wear all your clothes without the need to take off anything, pants over other pants, windpants over those pants. I think silk has been replaced by synthetics and merino wool as the best, whereas 10+ years ago it was #1,

Adam Keller, do you have any specific brands or garments of Merino wool you would recommend?

I currently own and wear Ice Breaker, Patagonia, and Helly Hansen merino wool base layers. I buy them when they're on sale, and they last for years. The extra price is definitely worth the quality and performance.

After many years of using poly base layers for winter hiking/mountaineering in both the mountains of New England and the Sierra, last year I bought several short and long-sleeve merino wool tops from the major suppliers, including SmartWool, Ice Breaker and others. I did several dozen dayhikes using the merino, but no multiday trips, so can't comment on its odor repelling abilities. However, in terms of keeping you warm while wicking away moisture to other layers - I couldn't see a bit of difference! Given the fact that merino is rather expensive, requires careful washing/drying, tends to shrink (the sizing runs small in my experience) - my advice is - buy poly base layers. You can buy 4 of them typically for the price of one merino wool base layer.

After many years of using poly base layers for winter hiking/mountaineering in both the mountains of New England and the Sierra, last year I bought several short and long-sleeve merino wool tops from the major suppliers, including SmartWool, Ice Breaker and others. I did several dozen dayhikes using the merino, but no multiday trips, so can't comment on its odor repelling abilities. However, in terms of keeping you warm while wicking away moisture to other layers - I couldn't see a bit of difference! Given the fact that merino is rather expensive, requires careful washing/drying, tends to shrink (the sizing runs small in my experience) - my advice is - buy poly base layers. You can buy 4 of them typically for the price of one merino wool base layer.

For merino wool base layers also look at IBEX. They are competitively prices with Smartwool, et al, but their stuff is made in the USA (not all, but most), not China. It's a Vermont company that puts out great stuff and it's well worth supporting them. They also offer, I believe, a lifetime guarantee.

Brynje of Norway: http://www.brynje.no/index_eng.html. Expensive, but breathes well, insulates well, and lasts a long time. Look at the Super Thermo range, in the first instance.

My experience is different from KRooney's. I have used poly base layers include bargain ones and many different high end synthetics (Patagonia Capilene 3, Marmut, REI, Saloman, HHDry, others).

I find merino wool base layer garments the best. I shop for them on sale. They are a luxury in that they are expensive. But I find myself nursing/mending a few merino garments rather than getting a few more synthetics. Merino base layers feel more comfortable. The lightweight merino garments work well in both cold and warm weather.

Merino seems to wick moisture well without getting the scratchy overheated feeling of the synthetics. If you know the gm weight of the merino material (150, 180, 200, 260 etc.), you can consistently judge what weight base layer(s) is(are) best for your activities.

The odor avoiding quality of merino is helpful if you are traveling, or on a long day trip, and can't launder as often as you'd like.

Among brands, there is still some variation depending on the individual garment style. I have found IceBreaker the most consistently best. There are plenty of great ones from SmartWool, Ibex, Patagonia and some from smaller brands like Minus33.

A couple of shopping suggestions: When possible, whether top or bottom, choose items with gussets (sleeve or crotch). It adds to the comfort. The better brands usually incorporate gussets.

In the beginning, go for the 100% merino material. Even some better known manufacturers make merino/synthetic blends, that sometimes include "Merino" in the name. Once you have experience with merino, it's easier to judge the price/performance ratio of the blends.

If the prices were lower, I'd experiment with some of the dressier merino clothes for less casual situations.

Cool Tools has listed merino/Icebreaker posts previously:

http://kk.org/cooltools/archives/1045; http://kk.org/cooltools/archives/5844