What is the best base layer?

I like their socks, and I do appreciate their 150 shirt series. I recently came back from a three week trip to Europe. I decided to adopt some of the (ultra)lightweight principles encouraged here (and at onebag.com). I was able to fit all my stuff into a single carryon bag for the flight. In there were 3 pairs of their marino socks and three marino 150 weight shirts. Despite being quite muggy out, I was able to get through the whole 3 weeks with only cycling through the shirts. Mind you, I did wash them once, but more out of patterned-behaviour than out of need. These shirts were light, durable, cool when wanted, warm when wanted, and never took on any odour. With one of these shirts and access to a stream to bird-bath you don't need to worry about this week's "Mike C's tip of the week".

I like polyester. I have all kinds of the stuff, from silk weight to Synchilla. It sucks up the sweat and fights the rain.

Depends on conditions. We talking winter or summer? Are you a thin body type that does not sweat as much as your body thermal index is higher. AKA more surface area to body mass and therefore lose heat faster than a thicker stockier build.

Winter you want a tight fitting base layer as you shouldn't be sweating and it equals best option for warmth/weight. Summer you want loose as you will be sweating and need to breathe. Of course the shirtless option is ok for a while until your skin burns at high altitude. Not recommended.

Wool even in the thinnest shirts is still warmer than cotton or name your plastic shirt. Yes, its far warmer when wet which is #1 when hiking in the shoulder seasons IMO. Most folks think merino wool doesn't stink as bad as cotton or name your plastic shirts, though pretty much its a toss up between merino and cotton IMO.

Thin high quality wool feels wonderful on your skin. Just like cotton and unlike name your plastic shirts, though several new types have come out that aren't bad at all. Its not your fathers polyester!

Wool is far more expensive. Winter or shoulder seasons –> WOOL. Polypro for summer and because it retains very little moisture and dries fast. I carry both and wear one or the other depending on conditions. Both are long sleeved.

Really hot days, its cotton all the way. Don't own silk, but supposedly silk is wonderful as well. Sorry, don't know. Out of my price point.

Polyester, summer or winter or in-between.

–B.G.–

I am a recent convert to Icebreaker merino 150 t-shirts as a baselayer. I used to use Polyester T-shirts and button up shirts. The two main problems I had with polyester were that I sweat a lot, so no matter what baselayer I wear it gets wet through. With polyester as soon as I stopped or a breeze picked up, the polyester would get cold and the cold wet top would feel horrible! With merino, I still get wet through but it feels so much more comfortable when I stop.

Polyester would also have a habit of roughing up under my rucksack shoulder strap, making my shoulder sore. Merino stays much softer even when wet so makes my shoulders much more comfortable. Finally, it is much more resistant to smelling after use, so I managed to get a good weeks use out of a single t-shirt and it still smelled fine. Same can't be said for my Icebreaker sock mind… they went stiff and smelt like a dead rodent!

After decades using various always improving synthetics, I have been won over to merino wool, short-sleeved micro-weight in summer and long-sleeved mid-weight in winter. Its hard to sort through all the claims of moisture transfer and thermal efficiency of either synthetic or wool, but the odor-surpressing of the better wools won me over. While I have my skepticism about some of Smartwool's claims, I find their products simply excellent. I used to bring one or two extra base layers on a four or five day strenuous trip–now one set does fine and cuts my pack weight.

Take a look at the article comparing wool and synthetic at http://www.backpackinglight.com/cgi-bin/backpackinglight/comfort_moisture_transport_wool_synthetic_clothing.html

Not sure there's a "best" per se; depends on conditions (temperature, humidity) and plain old personal preference.

One thing I look for besides fabric content is stretch. I'd just as soon not notice my baselayer; I want it to fit well so that outer layers fit over it comfortably but I hate that "compression layer" feeling.

I like merino. I think it's the most versatile across most conditions. I prefer 100% or with a small percentage of spandex (or similar) for a nice stretch. I also really like silk but silk baselayers don't seem to have caught on in this country as much as merino wool.

Icebreaker makes nice lightweight merinos but they don't seem to fit me well (narrow shoulders) and aren't very stretchy. Smartwool works better for me, in general, and I've gotten some I/O Bio pieces recently that I really like. Prices are more reasonable than Icebreaker or Smartwool as well. My all-time favorite baselayer top is an older Patagonia model; I can't find it anymore but I'll have to check out their Merino 2 line this fall.

Btw, I realized that my go to long-sleeved baselayer all summer long has been my super-cheap (I may even have gotten it for free with some sort of purchase promotion) Moosejaw logo long-sleeved cotton T-shirt. It's a fine cotton that dries quickly just with body temp with a really nice stretch. It feels like coolmax and I don't think I knew that it was cotton.

I have some midweight synthetic bottoms that I like (I think it's Polartec power dry) but not a fan of synthetics in general.

If base layer is only a next to skin layer then

Three season hiking- loose button down exofficio long sleeve

Winter- silk weight polartec powerdry

whatever wicks and feels comfortable … and dries quickly

thats all a base layer is supposed to do …

should be light as reasonable to facilitate wicking and quick drying …

i use synth myself

Patagonia made a Merino 1 top that was a mixture of syn and merino, for some reason (expense?) they quit making it, but this shirt (they never made a bottom that I'm aware of) is the best base layer (top) I own (and I own a bunch, both syn and merino). Light and dries quickly; has the odor fighting properties of merino, but is more durable w/ the inclusion of the syn

someone should copy this mix and come up w/ their own line

This past winter, I used a pair of midweight polyester/merino base layer pants made by Terramar. They were inexpensive and worked well. The polyester is against the skin, so I never felt any of the merino wool. I never noticed that my standard nylon hiking pants were soaking wet from the snow at around 32F/0C. And, they kept me plenty warm the night and day before when temps were down to around 20F/-6.7C, but with dry outer pants. Anyway, the main lesson I learned is that a pair of softshell pants would've worked better at temps <= 20F/-6.7C. (I was carrying WPB hardshells, but never had the need to put them on.)

For a shirt, I like a thin polyester running shirt, or very thin polyester fleece at colder temps. I've never tried a wool shirt though.

Merino wool. Doesn't matter whether it's winter of summer, rain or dry. Wool stays warm when wet. Wool breathes. I wear Smartwool, Icebreaker and Ibex. In summer, I were Icebreaker 140 tee shirt – to me they are cooler than cotton.

i like to do merino top/poly bottoms. an unspoken nice part about the merino is that every once in awhile i'll end up smelling very similar to my dog (usually after a thunderstorm) and that always brings a big smile to my face.

imo the only real benefit of wool is that it doesn't reak after a day of sweating (that's really the only benefit i see over poly). for some reason the poly bottoms don't bother me, so i wear them…

+ 1 on mikes suggestion. i'll add that patagonia's wool 2 midlayer is of the same blend and is also quite light. This blend is the best of both worlds: wicks & dries quick like synth, warm when wet and stench free like wool.

I use a lightweight i/o bio hoody now b/c i like the design and pure wool works plenty well, but i think patagonia has the best fabric blend for base.

>> Patagonia made a Merino 1 top that was a mixture of syn and merino, for some reason (expense?) they quit making it, but this shirt (they never made a bottom that I'm aware of) is the best base layer (top) I own (and I own a bunch, both syn and merino).

I think that's the "older" Patagonia top that I was talking about. My all-time favorite, too.

RAB has just added a new line of blend tops and bottoms to their apparel. They come in 120 g and 165 g and are a blend of 65% merino and 35% Cocona.

I'm going to have check out the 120 gram ones- now that's light!

I think supplex fabric is best. I make my own. Don't know if anyone makes one.

It is lightweight, absorbs little water, and dries quickly

I don't know about wicking. I think that's a bogus concept. You should regulate warmth to minimize sweating. And you want it to absorb little water so it will dry quickly. But wicking? I think maybe that's just marketing hype. But, this is probably a controversial idea.

It is also good by itself in warmer weather – sun protection, weave is very tight so bugs can't bite through it

One shirt/pants provides for all your needs so over-all kit weight is minimized

there are times you cant always regulate yr temperature properly for some time periods … especially for high exertion activities

the moisture then IMO needs to get away from the skin ASAP

Hi Guys,
Thank you everyone for their great input.

Jerry has brought up a very good point of a fabric (supplex) being bug proof. Any other types of fabric that are dense enough so bugs do not sting through? It is very important to me as I cannot enjoy myself with bugs around and biting thorough. Even if there is only a few of them. This supplex sounds interesting. I like that mosquitoes cannot sting through it but I would prefer to buy a ready piece of clothing though. Any suggestions?

@Chris. What is RAB? I have not found anything on internet.

@Andrew. Thank you for the link. Although it is from 2006 I do not think that too much has changed since then, has it?

I think that after reading everything (including the link provided by Andrew) it looks like merino is better in general. It does not dry as quickly as synthetic but as it dries out it is more comfortable to wear which is quite important. I do not see any other advantages of synthetic over merino and the stench factor is very important to me. I am surprised that Capilene is still quite bad when it comes to that. I thought that their anti stink system was more effective.
I will consider though a mixed blend from Patagonia.
Someone mentioned that Icebreaker did not fit them too well (too restrictive). It is something to consider as well. I have not thought about it before.
Thank you.

They’re a UK based company. RAB USA

I bought two lightweight Merino wool shirts on sale oat REI a couple of months ago. One was Ibex (100% Merino wool) and the other TNF (80% Merino wool) I have worn them on day hiking and backpacking trips this summer in temperatures of 80-100F. I thought they would be too hot in the higher temps, but they have been very comfortable. I hand wash the Ibex in cold water and a weak solution of Dawn dishwashing liquid with successful results. I figured if they use Dawn to wash oil covered baby ducks, it shouldn't be too harsh for a wool shirt. I accidentally washed the TNF wool shirt in the washing machine along with my other shirts, but it didn't seem to hurt it any. I am beginning to like Merino wool.

For 2-3 years I have been using base layers made by a Swedish based company named Woolpower and I am very pleased with them. Their garments are made of a mixture of merino wool (2/3) and synthetic fibers (1/3). This makes for excellent weight-warmth ratio (also in wet weather), non-smelly (sorry Mike C) and fantastic moisture wicking capabilities.
Finally, the Woolpower fabric is friendlier to your skin which is very important in my case compared to for example the 100% merino wool garments by Icebreaker.

See http://www.woolpower.se/en/asp/material_1.asp for more information (no, i don't own stocks).