Our Verdict
Our Analysis and Test Results
The Mountain Hardwear Airmesh's technical fleece and extremely lightweight face fabric make this base layer a standout. Warmth retention seems almost too good to be true, with breathability that's off the charts. The Airmesh is a fantastic choice to wear while on the move, with fabric designed to wick perspiration away from your skin, while providing a thin layer for warm air to get trapped. All this in a base layer that's a fraction of the weight of other tops, making it a good choice for those who pack light. The big downside is durability: the Airmesh works best next to skin and safely underneath another layer.
Likes
The Mountain Hardwear Airmesh packs a ton of warmth in an incredibly lightweight package. This base layer feels almost weightless on the body and even more so when stowed away in our backpacks.
A size “large” Airmesh only came in at an astounding 5.9 ounces – half as much as other base layers in our lineup.
On-the-line dry times were also excellent for the Airmesh, which suggests this base layer will dry quickly while wearing and perspiring – and a dry base layer keeps you much, much, warmer and more comfortable than a heavier, damp base layer.
The extremely hydrophilic, airy “mesh” of the Mountain Hardwear Airmesh's insulation is its secret weapon: most of this baselayer is devoted to the insulation, with only a thin outer face fabric to keep it all together.
For high-output activities, the Airmesh makes a great choice under a mid-layer and outer layer: winter hiking, snowshoeing, ski touring.
For summer, wear the Airmesh under a light wind jacket or sun shirt to keep comfortable on brisk mornings and evenings when you're eating up the miles. Performance may be even better if you wear this base layer inside-out, with the fluffy insulation on the exterior.
Dislikes
The biggest reserve we have with the Airmesh is the relative delicateness of the intriguing fabric being used. It was enough to prevent us from recommending it for everyone and everything.
The outer face fabric provides some margin of protection for the extremely plush, light fleece-like material underneath, but it's no match for any passing branches you may come into contact with. We picked up small tears on some of our more adventurous hikes off-trail.
If you're planning to wear the Airmesh under other layers or in more protected spaces, like while sleeping in a tent, this issue shouldn't be as big a deal, but it does limit the Airmesh's versatility.
Washing and drying also need to be done carefully; consider washing the Airmesh in a mesh wash bag in a machine, or hand-washing it, and always drying it on the line.
Fit was also a little peculiar, as this base layer runs large for its size. Measured length is ~30" for a men's size "large": on the taller side when compared to other base layers in our lineup. Fit is also loose; whereas many of the base layers we've tested have more of a close-to-skin fit that promotes good layering and transfer of your perspiration between layers. Knowing this, we might have chosen to size down intially.
Layering ability is somewhat limited to base-layer duties only, which the Airmesh does indeed excel at. But we appreciate the thumb loops, which really do help keep sleeves from wandering under other layers, while also providing good coverage when you take gloves off and on. We were also happy with the shoulder design, which relocates seams away from the top crest of the shoulders, which can be a point of irritation when lugging a heavy pack.
Should you Buy the Mountain Hardwear Airmesh?
If you're expressly looking for a super lightweight and hyper-breathable synthetic base layer top that dries faster than almost anything, the Mountain Hardwear Airmesh has got you covered. Keeping you dry by being ultra-breathable is the Airmesh's secret to also keeping you warm and comfortable.
What Other Base Layers Should You Consider?
For a super lightweight Nuyarn wool/blend option, check out the Ibex Woolies Pro Tech Crew with a slim fit that wears snugly on the wearer, allowing perspiration to transfer quickly through the fabric. For a more durable pick that's just as lightweight and breathable, check out the Patagonia Capilene Midweight Crew. The Capilene won't be as warm, but it's a great choice if you're tough on gear. For an ultimate warmth-to-weight base layer, look no further than the Burgeon Alpha Direct 90 Hoodie, whose Alpha Direct fabric has no protective face fabric to speak of, dedicating almost every inch and gram to its insulation.
| Awards | |
|---|---|
| Price | $90 List Check Backcountry (on sale!) |
Overall Score ![]() |
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| Star Rating | |
| Bottom Line | This lightweight synthetic base layer packs a surprising amount of warmth, while also being surprisingly breathable |
| Pros | Astounding warmth for its weight, excellent breathability, impressively fast dry times |
| Cons | Delicate fabric prone to rips, best used under another layer while active, looser fit than expected |
| Rating Categories | Mountain Hardwear Ai... |
| Warmth (25%) | |
| Breathability (20%) | |
| Comfort and Fit (20%) | |
| Durability (15%) | |
| Drying Speed (10%) | |
| Layering Ability (10%) | |
| Specifications | Mountain Hardwear Ai... |
| Fabric Weight Class | Lightweight |
| Material | 100% Polyester |
| Fit | Loose |
| Odor Control Fabric | Anti-odor finish |
| Time to Air Dry | 35 min |
| Thumb Loops | Yes |
| Dryer Safe | Yes, tumble dry low |
| UPF Sun Protection | None listed |
| Seam Stitching | Overlock seams |
| Shoulder Top Seams | No |
| Drop Tail Hem | No |
| Measured Weight (Size Large) | 5.6 oz |
| Measured Shirt Length (Size Large) | 30.0 in |
| Available Cuts | Crew, Half-Zip, Hoodie |













