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Index: Base Layers

There are a ton of base layers out there, and with all those choices, you might be tempted to just grab one off the shelf. But there are some details worth paying attention to, such as the type of fabric, and the weight, thickness, warmth, and wickability of a particular piece.

To narrow things down a bit for you, and to clarify some of your options, we’ve listed some of our favorite base layers that we wear on any given day in the mountains or around town.

We’ll be adding to this index going forward, but it should give you a head-start in shopping for a new layer.

We’ve split these products up into loose categories based on their material—ranging from pure merino wool, to merino / synthetic blends, to fully synthetic fabrics. We’ve also included an underwear section at the end, with our take on some more athletic underwear options

Also note that the both the wool and wool-blend base layers have a weight listed. This should give you a relative sense of how thin or thick those pieces are. (A fabric with a weight of 150 g/m2 is quite thin, while a 250g/m2 piece will be quite a bit thicker and warmer.)


Icebreaker LS Siren Crewe (Women’s)

Weight: 150 g/m2
Material: 96% merino wool, 4% elastane
MSRP: $89.99

We recommend the Siren Crewe to any women looking for a base layer for any outdoor activity, though it’s nice to wear on down days, too. It’s a thin, soft, comfortable a go-to top.


Smartwool NTS Micro 150 Henley and Crew

Weight: 150 g/m2
Material: 100% Merino wool
MSRP: $90

The NTS Micro 150 Henley and Crew were excellent pieces on very warm ski tours down in New Zealand. The lightest weight layers in SmartWool’s line, they take up little room in your bag, and they look good off the mountain (we’re particularly big fans of the “Taupe” color henley). If you’re looking for light, thin layers, we can vouch for these.


WoolX Base Camp Hoodie

Weight: 165 g/m2
Material: 100% Merino wool
MSRP: $111

This “all season 1/2 zip hoodie” has become one of our new favorite base layers for touring. At a weight of 160g/m², this lightweight piece works comfortably next-to-skin, but it can be worn over a thin t-shirt, too, while still being light enough to wear beneath slim-fitting, midlayers (like the Arc’teryx ProCline Hybrid Hoody). We found ourselves using the hood for sun protection more than we thought we would on the skin up, then using it again on the summit if the winds picked up. Lightweight warmth, comfortable feel, a clean style, and a low-profile hood that stays out of your way when not in use.

Jonathan Ellsworth reviews the Woolx Basecamp Hoody for Blister Gear Review

Jonathan Ellsworth in the WoolX Basecamp Hoody, MT. Cheeseman, NZ.

Patagonia Merino Air Hoody

Weight: 190 g/m2
Material: Merino Wool / Capilene Blend
MSRP: $149

The Merino Air is an unconventional base layer with unusually good performance characteristics. It feels warmer than you’d expect for its 190 g/m2 weight, and even with a soft, stretchy feel thanks to a merino / Capilene blend fabric, it resists getting stinky as well as any 100% merino layer we’ve used.

Jonathan Ellsworth reviews the Patagonia Merino Air Hoody for Blister Gear Review

Jonathan Ellsworth in the Patagonia Merino Air Hoody. (photo by Justin Bobb)

Mons Royale Monsie

Weight: 190g/m2
Material: 100% Premium Merino
MSRP: $239.00

It’s the ultimate onesie. The Mons Royale Monsie is awesome, so you should get one. And our full review contains cute puppies, axes, sexy Hawaiian photo shoots, Looney Tunes onesies, and more, so you should read it.

Review of the Mons Royale Monsie, Blister Gear Review

“I don’t always wear a onesie, but when I do, I prefer the Monsie.”

Mons Royale Supa Tech LS

Weight: 190 g/m2
Material: 95% merino; 5% Elastane
MSRP: $109.00

What smells better than a Mons Royale Supa Tech LS base layer after about 30 days of hard use? Not much, actually. If you’re not into the knit-sweater look of the Patagonia Merino Air, or want something a tad cheaper, it’s a great choice.


Icebreaker Sprint L/S Crewe Shirt

Weight: 200 g/m2
Material: 97% Merino Wool, 3% Elastane
MSRP: $100

Slightly heavier than the Mons Supa Tech (above), the Icebreaker merino wool Sprint Crewe (and the “legless pants” that can pair with it) is an excellent performance base layer. Comfortable, breathable, fast drying, and odor free; thank you merino.


SmartWool NTS Mid 250 Pattern Crew

Weight: 250 g/m2SmartWool Midweight Patterned Crew, Blister Gear Review

Material: 100% Merino Wool
MSRP: $100
After more than a year of testing, the SmartWool NTS Mid 250 Pattern Crew base layer has become an all-time favorite. It’s the warmest of the wool layers listed here, but it’s a very comfortable layer for everyday use or as a base layer for lift-accessed skiing and riding.
Women’s NTS Mid 250 Pattern Zip (Women’s)

Weight: 250 g/m2
Material: 100% Merino Wool
MSRP: $110

The 1/4-zip women’s version of the layer above.




Lululemon Swiftly Tech Long Sleeve Crew (Womens’)

Material: Silverescent® fabric
MSRP: $68

The Swiftly Tech Long Sleeve is a light, comfortable, versatile base layer than can be used for a broad range of outdoor activities, year round.
Polarmax Comp 4 Tech Fleece Crew , Blister Gear Review.
Polarmax Comp 4 Tech Fleece Crew

Material: Heavyweight 4-way Acclimate dry stretch fabric
MSRP: $50

A warm, very durable synthetic piece that is our bang-for-buck choice among synthetic layers.


Mountain Equipment Eclipse Hooded Zip Tee

Material: Pontetorto Technostretch fleece
MSRP: $140.00

Not the best choice if you’re looking for something to just wear around town or out on dates, but if you’re looking for a refined, warm, technical mid-layer for cold days in the mountains, then take a look.

NEXT: Underwear

1 Comment

  1. alvin baker November 15, 2015 Reply

    Do you (or someone) know of any silk baselayers of sufficient durability for outdoor use? Also, how about something regarding yak wool…I have read some good things about that, but never seen it reviewed by outdoors people.

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