Baselayer Research and Applications

Bump79

WKR
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Intro:​

I've done a lot of research into materials lately and learned a lot. Big one is why I haven't been as satisfied with my merino as I used to be. This is largely due to moving from the Rockies to the South. I still do a lot of hunting out west but I've noticed that whitetail hunting here with higher humidity my go-to clothes aren't performing like they always did, new stuff I purchased I didn't care for at all, or on the other coin some pieces that I always liked I now love.

The reason I took the time to write this up is because I don't feel that all hunting companies (some are) are being transparent with the uses. This doesn't mean they are being deliberately deceitful but rather omitting info just to make a sale. It's also rather complicated that most people just go with the trends (that's what I did).

Here's what I've learned and please correct me if any information or is incorrect. None of this was done to say one material is better than the other but to provide information and let people decide what's best for them outside of the Instagram hype. Please also preface this that this is purely based on material properties and weights as I can't take into account all of the weaves in different textiles.

Material properties:

Merino - Holds up to 33% of it's weight in water (which is still substantially better than cotton at 2,300%). The unique part of merino is that it holds it's water in the core of the fiber and the exterior stays dry. Giving it a dry to the touch feeling and reducing it's thermal conductivity (making it warmer when wet). It is also very breathable fabric, especially in lower weights. It is also much heavier than polyester and nylon.

Polyester - Lightweight synthetic and holds only .3% of it's weight in water and nylon holds 30% and hold that water on the exterior, making it dry quicker than merino and nylon.

Nylon - Lightweight durable synthetic but holds approximately the same amount of water (30%) as merino but is more thermally efficient because the water is on the exterior of the fiber (making you colder). Technically the breathability of the fiber is less but in my experience this isn't as relevant as it is a more durable fabric and can tolerate a looser weave.

Polypropylene - A lesser used clothing fiber from what I can find and holds almost no water at all. Making it have great thermal and dry the fastest of all.

Cotton - Holds an incredible amount of water, is heavy, durable and shrinks. Cotton is for dry environments and busting heavy brush, not in a base layer.

Uses:

It is critical to emphasize that each application has it's own need and there really is NO perfect base layer for everyone. There is however, an ideal base layer for you in a certain condition. I've broke it down into 4 different factors: User Perspiration, Temperature, Humidity and Activity.

In my opinion this all boils down to one thing. Sweat! It is what we are asking the base layer to do and those 4 factors are what plays into the amount and the evaporation of sweat.

User Perspiration Level​

Based on the material properties above you might gather that if you tend to sweat your ass off the same layer that works for your buddy that seemingly never sweats won't work for you. This is critical when selecting a base layer and to me this is the #1 factor. If you are a heavy sweater then a material that gives away moisture better (polyester or polypro) is going to be more ideal for you. You might never want a 100% merino piece and need a blend down the merino content depending on the remaining factors (temp, humidity, activity). If you sweat a lot and the merino isn't giving up the moisture, breathability goes down and sweating goes up making for a less than enjoyable hike.

If you're like me and just came back from the gym wearing a merino top just to try it out and got out with little to no perspiration then you might benefit more from merino. I'm not saying this as a brag as I'm really not in great shape, I just don't sweat. This is because the material will easily evaporate out the little sweat you do produce while keeping you warmer than polyester. In some conditions you want to hold the moisture you to get a cooling effect.

Temperature​

Temperature not only affects the weight of the base layer you are using (grams per square meter or GSM) but it should affect the material selection as well. Remember everything plays into together and you are trying to get the sweat to evaporation ratio right.

If it's a hot and dry climate a lightweight breathable merino can actually give a cooling effect as it absorbs the moisture and releases it slowly.

Humidity​

Humidity is a big factor in how quickly water will evaporate. In a high temperature high humidity condition you are going to perspire a lot and not give it up. Reducing breathability and in turn making you perspire more. Merino is a poor choice in this application.

In a low humidity condition like the desert or Rockies you will burn off sweat quickly. So a higher content merino piece is more logical in this application.

Activity​

This is simple. If you have high activity you will perspire more. More active you are then the more you will benefit from a merino blend (if you don't sweat much) or synthetic (if you sweat a lot).

One thing that has been bothering me is the amount of whitetail hunters that have been buying backpack hunting gear. This isn't to knock whitetail hunters but I truly believe that the application is completely different. Hiking 3 miles in the dark to sit on a windy glassing nob overlooking a snowy expanse is different that hiking in a half mile and sitting in a stand when it's freezing out. It's both hard conditions but you need different stuff. There are pieces that overlap but that shiny loud puffy you love on the mountain is terrible for a stand. Rant over... back to base layers.

Weights:

Now once you figure out what material is best for you, then you can select the weight of the material based on temperature.
  1. Ultralight (150 gsm minus)
  2. Light (145 - 175 gsm)
  3. Medium (175 - 210 gsm)
  4. Heavy Weight (210 gsm plus)
For me, I don't see a place in my arsenal for a heavy weight merino and I find myself rarely using anything over 180. In my opinion at that point you are better off with a fleece with loft to get the warmth you need. This is because as the weight (added in thickness or tightness of weave) reduces the breathability will go down. It is also more durable and versatile.
 
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Bump79

WKR
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I'll try to summarize this better.
  • If you sweat a lot - Use merino sparingly.
  • Early season in the hot humid area - avoid merino completely
  • Hot as hell in the desert - an ultralight merino (or merino nylon blend) is a good idea
  • Dry and cold - Mid weight high content merino works well.
  • Humid, wet and cold sit in the stand - Mid weight 50/50 merino blend works well.
  • Active hunt in humid, wet and cold - Low merino content might be best.
 

5MilesBack

"DADDY"
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I've been chasing elk for 40 years so I've tried just about everything out there in that time span. I still laugh at a time back in the early 80's when I saw an ad in a catalog for some "new" base layers, and their ad said "Laugh at the Cold". So my buddy and I bought some. On that next hunt I still picture my buddy telling me "laugh at the cold, my ***".

These days I pretty much stick to the archery season in warm September. But I sweat my tail off every single day running those mountains.......to the point of what I call "sopping wet". And 100% lightweight merino base layers are an absolute Godsend for keeping me the most comfortable. I can't stand the synthetics basically just rubbing back and forth over my sweat covered skin and not keeping up with getting it away from my skin. At least merino absorbs it, and from my experience.....transfers it to my outer layers. And when I hit the sack every night, they always seem to be dry already to me.
 
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Bump79

WKR
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Oct 5, 2020
Messages
923
I've been chasing elk for 40 years so I've tried just about everything out there in that time span. I still laugh at a time back in the early 80's when I saw an ad in a catalog for some "new" base layers, and their ad said "Laugh at the Cold". So my buddy and I bought some. On that next hunt I still picture my buddy telling me "laugh at the cold, my ***".

These days I pretty much stick to the archery season in warm September. But I sweat my tail off every single day running those mountains.......to the point of what I call "sopping wet". And 100% lightweight merino base layers are an absolute Godsend for keeping me the most comfortable. I can't stand the synthetics basically just rubbing back and forth over my sweat covered skin and not keeping up with getting it away from my skin. At least merino absorbs it, and from my experience.....transfers it to my outer layers. And when I hit the sack every night, they always seem to be dry already to me.
Thanks for the feedback! I can attest to 100% merino pieces having a high comfort level. I've seen you post elsewhere that you run a lightweight merino, which is part of what I was trying to convey. A 150 gsm or lower merino dries pretty darn quick because of it's breathability. Higher weight than that and the merino loses some breathability and seems to hold water. Have you had any luck with lightweight poly merino blends?

When it comes to synthetics my personal opinion is that for them to be really effective they need to be extremely snug. Like Under Armor hot gear snug and that you look like a d-bag without a mid layer on. To me this is because by holding less water the poly is less wicking than merino so it needs to be directly on skin to transfer the moisture out.
 

5MilesBack

"DADDY"
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Have you had any luck with lightweight poly merino blends?
I've tried a few different blends, but haven't found them to be more comfortable for me. I thought the Patagonia merino/capilene blend would be the ticket, but didn't like those at all. So I stick to 100% merino and haven't been disappointed so far. And I wear them 24/7 for elk hunting.
 
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Bump79

WKR
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I've tried a few different blends, but haven't found them to be more comfortable for me. I thought the Patagonia merino/capilene blend would be the ticket, but didn't like those at all. So I stick to 100% merino and haven't been disappointed so far. And I wear them 24/7 for elk hunting.
A little background on where I'm coming from and why I wrote this. I grew up in Montana and have hunted my whole life then moved down to Kentucky since my wife is from here.

After being here I've gotten into whitetail hunting and the humidity is nearly always sky high and I am more stationary. So what I've noticed is that my 100% merino layers went from feeling warm when wet and drying quickly... to just wet and kind of cold. The humidity isn't allowing the merino to dry as effectively and just isn't performing the same.

I will still wear my 100% 150 gsm quarter or half zip out west but I'm trying a poly blend now to address this issue.
 

sneaky

"DADDY"
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100% merino takes forever to dry compared to blends or synthetics to me. I hate feeling clammy in 100% merino. I like the no stink properties, but hate that constantly damp feeling with it. You're right, add that on to high humidity and merino can be miserable.

Sent from my SM-G955U using Tapatalk
 

5MilesBack

"DADDY"
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After being here I've gotten into whitetail hunting and the humidity is nearly always sky high and I am more stationary. So what I've noticed is that my 100% merino layers went from feeling warm when wet and drying quickly... to just wet and kind of cold. The humidity isn't allowing the merino to dry as effectively and just isn't performing the same.
Ya, if I wasn't constantly on the move or wearing the same pair for days on end, I'd stick to synthetic. I've seen this before.......whitetail treestand hunters getting merino because they hear such great things about it and then they're very disappointed with it.......but those conditions are not where it excels.
 
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Bump79

WKR
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Ya, if I wasn't constantly on the move or wearing the same pair for days on end, I'd stick to synthetic. I've seen this before.......whitetail treestand hunters getting merino because they hear such great things about it and then they're very disappointed with it.......but those conditions are not where it excels.
Absolutely. That's the primary reason I wrote this because once I really dug into the material properties it made sense to me why they don't perform in some conditions. Companies like First Lite offer only merino baselayers and they are all the rage in the Whitetail world right now. It will work for some in certain conditions, but not all.

I've been been bouncing back and forth between an extremely breathable polyester base and a blend in similar conditions. I still prefer the feeling on skin of the merino blend vs the full synthetic.

I'll play around this fall and keep this thread updated as I play around in both Montana and KY with all merino, blend and full synthetic in varying conditions.
 

RoseAllen

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I have found anything heavier than Kuiu's 125gm wool and sitka's 120gm wool next to skin breathability goes way down. Also drys fast in hi humidity as well. Fish net base layers or a game changer as well.
 

jd1006

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I think companies are taking the merino blends too far, and I wonder if that’s more for cost purposes than it is for enhanced breathability and durability. The Merino6 that Stone Glacier uses has a high % of merino and has a weave that is very durable. Also, I’m with Jason Hairston and think that any spandex/elastane is bad for baselayer blends.
 

280ack

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New Hampshire
Bump, Thanks for posting the info. I have been hunting since the days of waffle knits and Duofold blends. I now have two weights of "poly" and question if I need more.
The next hunt will be mid-Oct at 8,600 + feet elevation, where temps can be 40 to 0 and 6 days long on horses, lower exertion. I currently do not own any merino and after reading this column I am not sure I need it. Drying out merino seems like it would be a challenge in the backcountry at or below freezing. Is spending $400.00 + on two sets of merino needed when polly that has served well is already owned? I am sure its good stuff but needed ?
 

jtivat

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I think companies are taking the merino blends too far, and I wonder if that’s more for cost purposes than it is for enhanced breathability and durability. The Merino6 that Stone Glacier uses has a high % of merino and has a weave that is very durable. Also, I’m with Jason Hairston and think that any spandex/elastane is bad for baselayer blends.
Ya the main reason I like merino is the odor free aspect not sure how it would keep this with other fabrics added in?
 
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If you haven't seen this thread yet, give it a read:


Basically it's a look at the question of what happens when you think of the material properties in 3D. Add a bunch of fiber surface area for evaporation, some "windows" for direct perspiration loss and some air pockets to keep you warm and things start really getting interesting. I'm also starting to wonder about the different spinning techniques for incorporating synthetic fibers with wool.
 

Seeknelk

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If you haven't seen this thread yet, give it a read:


Basically it's a look at the question of what happens when you think of the material properties in 3D. Add a bunch of fiber surface area for evaporation, some "windows" for direct perspiration loss and some air pockets to keep you warm and things start really getting interesting. I'm also starting to wonder about the different spinning techniques for incorporating synthetic fibers with wool.
Im waiting for my sexy fishnet merino shirt myself😎. I think that under either a Sitka lightweight synthetic hoody or heavier grid fleece might ,maybe cover a ton of bases.
 
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