Brynje Super Thermo LS Shirt

Absolutely the best base layer fabric by a mile. At least, for conditions where you can wear a second layer of some kind, on top.
It doesn’t really work well as a stand alone layer, due to a lack of wind and sun protection when worn by itself.

Let’s start with what took me so long to get one of these synthetic (polypropylene) versions:
I was afraid of polypro’s notorious stink.
It turns out that these do not suffer from that. I don’t know if it’s the mesh, or the fabric treatment or both, but I have worn this for 5 days straight of heavy sweating on an hut trip, and it was not gross. The same as my merino base layers would have been.

The fabric also feels nice and soft against the skin.

Now for performance:
This is so much better than any other baselayer (and I have tried a ton of different fabrics). Miles better.
It breathes (obviously) a million times better than any regular fabric.
It soaks up far less water than anything else (including merino fishnet).
When you are soaking wet, it doesn’t feel cold and clammy, sticking to your skin
It dries way, way faster than any other fabric.
It ventilates much better than any non fishnet fabric.

So, for me, I can wear this under a thin shell, with good vents. When I start to get hot, I open zippers or push up sleeves, and dump a lot of heat because of the net structure. When I get cold, I do the reverse and the fishnet provides a reasonable amount of warmth. (Similar to other lightweight base layers when those are dry).

The big benefit is for times when you can not vent enough:
I spent a day skiing lift served on the Gemstock in Switzerland. 5000’ vertical laps. I wanted to keep my shells fully zipped up for when I’d fall. The sun and warm temps, on the lower half of the mountain, combined with hard work skiing the heavy snow, made me sweat like crazy. Then, we’d have 30-45 minutes of standing around and riding the trams to the top.
Getting off the tram at the top it was a lot colder, we were in a cloud, and windy. Despite being absolutely drenched in sweat at the bottom, I was merely cool at the top.
The same goes for sweating under a backpack. Take it off, wait a few minutes, and it would be fine.

Now for the not so good: the garment design:

The fishnet is great, so why do they insist on big knitted cuffs?
Those are some of the sweatiest, hardest to dry parts of a shirt. A simple edge binding like on the bottom hem would be great there.
Similarly, why does the women’s top have a solid panel in the front, and the bottoms have solid panels in the crotch?
They call it “modesty panels” but everyone I know wears underpants, and women a (sports)bra, underneath their base layers, so those areas are already not see-through, and could really benefit from the breathability of the fishnet.

Finally there is the fit.
The shirts run VERY long in the torso. Better too long than too short, but certainly the front hem could be a bit shorter.
The fit is a bit baggier than most fitted base layers. If ever there was a base layer that would benefit from a skintight fit, this would be it.
The sleeves are too short (at least on the XL’s I have). They are shorter than any other XL and the same or shorter than many L’s I have.

Need the blue shirt, with shoulder overlays, in a 2XL. But your sizing stops at Large (for small teens). Do you offer adult sizes?

Will you get them in white? I although it will never be a “normal” look without a layer over top, I think the white at least won’t be as glaringly “Marilyn Manson” on my past white flesh.

I usually wear an XL shirt; but, It’s is loosely fitted. Should I order the large so it will fit snugly?

This is when you know you have too many base layers but I have to admit, this thing rules. I have not used it in a race context yet (only intervals in training) but this paired with a race/speed top is pretty ultimate for anything where you are engaging in high output. When you pull it out of the box it does not look like it will be comfortable at all, like at all, and there is this weird nipple thing but just ignore all that crap because this thing delivers when used a prescribed - keeps you warm for the way down and cool for the hard work. Really great base layer.