BN3TH Merino Wool Base Layers Review: They Will Keep You Comfortably Warm During Winter’s Coldest Weeks

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The Lowdown

BN3TH Merino wool items are made from a fabric composed of 83% Merino wool, 13% polyamide, and 4% Spandex with a fabric weight of 200GM. The 200GM weight is the sweet spot for base layers, in my opinion. It is thick enough to keep you warm but still not so thick that it feels bulky or constricting.

Overall
5

Pros

Well-made

Comfortable

All the benefits of Merino wool with the added durability and stretch polyamide and Spandex

Long Sleeve Crewneck has thumb loops which are quite handy

Boxers and leggings have MyPakage Pouch Technology to support the male anatomy

All three pieces still look new after several washings

Cons

  • Limited color options
BN3TH Merino Wool Base Layers Review: They Will Keep You Comfortably Warm During Winter's Coldest Weeks Listen to this article

If you own a dog, you know the worst part of an otherwise wonderful experience is having to walk the pup in lousy weather. As a matter of fact, I just got back from a long walk with my older dog Nava in the freezing rain. However, I was toasty warm thanks to BN3TH Merino wool base layers.

Before we take a look at the three garments BN3TH sent me to evaluate, I thought we might take a moment to talk about why Merino wool is such a fantastic fabric.

You likely think of thick, often scratchy material when you think of wool. That may be the case for some types of wool, but Merino wool is an entirely different animal. Merino wool is soft and temperature regulating, and it doesn’t trap odors the way synthetics and cotton do.

Many people will wear Merino wool clothing for days at a time before washing, without the clothes ever smelling like they have been previously worn. Merino wool can be washed on cold and air-dried so you save on dry-cleaning; it even resists wrinkling, so you can keep ironing to a minimum.

There are, however, some downsides to Merino wool.

On its own, Merino tends not to be quite as durable as other materials. That’s why many companies add in a bit of nylon or other synthetics as well as Spandex to increase the ability of the material to stretch.

Due to the nature of Merino wool, it is impossible to get it in pure white. Some companies have come close, but the material is more off-white or looks dingy. That’s a bummer since Merino wool would make an excellent undershirt. It also means that, while I’ve replaced many of my dress shirts with shirts made from Merino wool, I still need to keep some cotton shirts around for times when I want a crisp white shirt under my suit jacket.

Finally, Merino wool is pricey. When I first got into Merino wool, I started by replacing my worn, stretched-out GAP t-shirts. Those GAP shirts cost me about $15 a piece. The Merino t-shirt that replaced them was at least $50, but many can cost double that.

The sticker shock alone may keep some from checking out Merino wool, but I bit the bullet, went to the expense, and am glad I did.

My Merino clothing is comfortable, keeps me at just the right temperature, and looks good. Once a week, I take the six items I’ve worn the most, machine wash them on the cold cycle, and then let them air dry. (I choose six items because that’s how many levels my drying rack has.)

I’ve even replaced most of my boxers and socks with items made from Merino; yes, there is such a thing as Merino wool underwear, and it’s great.

man wearing BN3TH Merino Wool base layers in black

BN3TH apparel offers items in a range of materials. Their selection of Merino wool clothing isn’t extensive, but the base layer items they sent me — a long-sleeve crewneck, long johns, and a pair of boxers — have impressed me.

BN3TH Merino Wool long johns, boxer briefs, crew neck long sleeve

All three BN3TH Merino wool items are made from a fabric composed of 83% Merino wool, 13% polyamide, and 4% Spandex with a fabric weight of 200GM. The 200GM weight is the sweet spot for base layers, in my opinion. It is thick enough to keep you warm but still not so thick that it feels bulky or constricting.

When I first got into Merino wool, I was a bit of a purist and only opted for items that were 100% Merino. Along the way, I discovered that some companies had been able to blend in just enough synthetic material to make the fabric softer, thinner, and more durable than it would otherwise be without losing the benefits that make Merino wool special.

BN3TH’s Merino wool offerings are a perfect example of that. They are so thin that you won’t expect them to be as warm as they are, but they are incredibly warm.

By adding in a bit of Spandex, BN3TH gives their Merino wool base layers just enough stretch that they hug your body like a second skin. That is, of course, what you want from a base layer. It is also why, unlike some base layers I’ve bought that can be worn on their own, at least in my case, the BN3TH offerings are genuinely meant to be undergarments.

In fact, because they are so form-fitting, I’ll be using stock photos in this review rather than pictures of me wearing them. You’re welcome for that.

BN3TH Merino Wool Long-Sleeve Crewneck

BN3TH Merino wool long-sleeve crewneck

Like all the items I received, the BN3TH Merino wool long-sleeve crewneck is black, but it’s also available in a spruce green camo. The material looks and feels great. It’s thin but feels substantial enough that I’m not worried about it easily ripping.

ThermoWorks Thermapen Mk4

BN3TH Merino wool long-sleeve crewneck back

You’ll find the BN3TH logo in white on the back of the neck. It’s not large enough to be obnoxious, and since I will wear this under other garments, I’m not bothered by it being there at all.

When you try this base layer on, the sleeves might seem a bit longer than they need to be, but that’s because they have low-profile thumbholes; these thumbholes serve two purposes.

First, when adding a layer over the BN3TH shirt, the thumbholes keep the base layer in place rather than the sleeves pulling as you slip into the next layer.

Second, when wearing gloves, these thumb holes let you keep the first extended beyond your wrist so no air can get between the shirt and your glove. That way, you stay even warmer when you are out in the cold. And when you aren’t using the thumbholes, you can double up the end of the sleeve and make it the “normal” length.

BN3TH notes that “This relaxed-fit thermal top easily transitions from a base layer to streetwear. “This may be the case if you are thin or have a muscular physique, but this 56-year-old isn’t going to do that.

Photo of the front of the BN3TH Merino wool long-sleeve crewneck

The BN3TH Merino Wool Long-Sleeve Crewneck is available in sizes from XXS to XXL for an MSRP of $105. That pricing may sound high, but it is in the mid-range of what shirts like this can cost. Add in the fact that you can wear this shirt multiple times before washing it, and the high price is somewhat balanced by the fact that you’ll need fewer items than you think. If you get two of these base layer shirts, you will be set for the winter months.

BN3TH Merino Wool Boxer Brief

BN3TH Merino Wool Boxer Brief in black

BN3TH also makes Merino wool boxer briefs from the same 200GM wool, polyamide, and Spandex mix. I’ve been wearing boxer briefs made from 100% Merino wool for over a year, and I am a fan. Like Merino shirts, some people wear their Merino boxers for multiple days between washing. I’m not one of them, but I still like the comfort and warmth of the material.

BN3TH Merino Wool Boxer brief back (in camo)

The BN3TH Merino Wool Boxer Brief is also available in spruce green camo.

The addition of Spandex in the BN3TH boxer briefs makes them a bit more form-fitting than the boxers I’ve been wearing, and as a result, they are even more comfortable. At $60 a pair, I don’t see myself replacing what I already own, but these would be a good option when I eventually need to replace them.

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The boxers have a 6.5″ inseam and a soft 1 3/3″ knitted waistband; the waistband doesn’t bunch or pinch, and it does a good job of keeping everything together.

Explanation of the BN3TH Merino Wool Boxer Brief "MYPAKAGE" Pouch Technology.

And speaking of “keeping everything together,” BN3TH added their “MyPakage Pouch Technology” when designing the boxers, which, as they explain, “lifts and separates your boys, eliminating the need to shift or adjust.”

BN3TH Merino Wool Boxer Brief in black

I have a pair of boxer briefs from Tommy John with a similar design. It’s an interesting idea but not a huge selling point for me. What is a selling point for me is that these boxers are thin, light, breathable, and they feel great.

BN3TH Merino Wool Full Length Base Layer

BN3TH Merino Wool Length Base Layer in Spruce green camo

The BN3TH Merino Wool Full Length Base Layer is also available in spruce green camo.

BN3TH also offers a full-length base layer based on the design of their boxer briefs. Made from the same 200GM fabric blend, they have a 29″ inseam, a soft 1 3/8 knitted wasteland, and the company’s “MyPakage” Pouch Technology.”

The BN3TH Merino Wool Full Length Base Layer is just as comfortable as the boxer briefs, and they will keep your legs warm all day long no matter what you are doing. At $95, they are just $35 more than the boxers, and they sit right in the middle range of pricing for leggings made from Merino wool.

Three views of a model wearing the BN3TH Merino Wool Full Length Base Layer

I’ve been wearing base layer leggings daily this winter and have never felt warmer. Some days I wear one of my pairs made from 100% Merino wool. They are warm but fit a bit loosely. Other days I’ll wear one of my pairs made from synthetic materials. They fit more snuggly and feel like a second skin, but they are never quite as warm.

BN3TH Merino Wool Full Length Base Layer in black

I absolutely love the BN3TH Merino Wool Full Length Base Layer because these leggings have the comfort and benefits of Merino wool while fitting a bit more snuggly, the way my synthetic leggings do. In other words, with this pair of leggings, I get the best of both worlds.

Switching to Merino wool is a pricey endeavor. However, the benefits of doing so are significant, and thanks to Merino’s odor-resistant prowess, you won’t need to swap out your clothing one for one. One Merino t-shirt can easily replace two or three cotton or synthetic shirts. Two or three leggings base layers can easily see you through the cold season. More importantly, if you live in a cold climate, you’ll be able to stay warm all winter long. Trust me, I know.

Last week, we had the first significant snowfall of the season, and my BN3TH Merino wool base layers kept me warm while I cleared the driveway and sidewalk. And this morning, as I walked Nava, with the temperature hovering at freezing and with cold rain coming down, I was so warm, thanks to their base layers, that I had to open my parka soon after beginning to walk.

I’ve worn and washed my BN3TH Merino Wool review samples several times, and they all look brand new. We’ll see how they hold up over time, but so far, they are proving to be a quality product at a fair (from a market perspective) price.

BN3TH Merino Wool Base Layers range in price from $60 to $115; they are available directly from the manufacturer.

Source: Manufacturer supplied review samples

What I Like: Well-made; Comfortable; All the benefits of Merino wool with the added durability and stretch polyamide and Spandex; Long Sleeve Crewneck has thumb loops which are quite handy; Boxers and leggings have MyPakage Pouch Technology to support the male anatomy; All three pieces still look new after several washings

What Needs Improvement: Limited color options

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About the Author

Dan Cohen
Having a father who was heavily involved in early laser and fiber-optical research, Dan grew up surrounded by technology and gadgets. Dan’s father brought home one of the very first video games when he was young and Dan remembers seeing a “pre-release” touchtone phone. (When he asked his father what the “#” and “*” buttons were his dad said, “Some day, far in the future, we’ll have some use for them.”) Technology seemed to be in Dan’s blood but at some point he took a different path and ended up in the clergy. His passion for technology and gadgets never left him. Dan is married to Raina Goldberg who is also an avid user of Apple products. They live in New Jersey with their golden doodle Nava.