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Arc'teryx Phase AR Crew LS Review

A quality crafted, super durable and warm synthetic base layer that can take a beating and keep going
arc'teryx phase ar crew ls base layer review
Credit: Arc'teryx
Price:  $79 List
Manufacturer:   Arc'teryx
By Roland Mott ⋅ Review Editor  ⋅  Nov 15, 2019
  • Warmth - 25% 7.0
  • Breathability - 20% 5.0
  • Comfort and Fit - 20% 7.0
  • Durability - 15% 9.0
  • Drying Speed - 10% 4.0
  • Layering Ability - 10% 8.0

Our Verdict

Arc'teryx discontinued the Phase AR Crew.
Super durable
Wind resistant
Good fit
Quality construction
Good price
Not comfortable next to skin
Not the best breathability
Gets stinky over time
A high-scoring synthetic layer, the Arc'teryx Phase AR Crew LS is a midweight base layer that is made of 100% polyester. It offers great warmth, superior durability, and a purposefully built quality fit. With an impressively stretchy material and a thoughtful design, this top is extremely mobile and encourages movement. This layer struggles in all the traditional areas a synthetic base layer does: not nearly as comfortable against the skin as a Merino and not as breathable, but a competitive price and supreme durability. This base layer is best used in situations where warmth is important, but breathability isn't the main concern. Also, any situation where you need a layer that can be dragged, kicked, smeared, scraped, or there will be any chimneying or groveling of any kind going on.

Our Analysis and Test Results

Made with a super durable, stretchy, and wind resistant synthetic fabric that Arc'teryx calls their Phasic AR, this base layer offers a midweight option that transports moisture and dries quickly for cooler temps. We liked this layer for its great fit, durable fabric, and stretch that was built for movement.

Performance Comparison

arc'teryx phase ar crew ls base layer review - a dialed-in design and a great fit for the phase ar. although the...
A dialed-in design and a great fit for the Phase AR. Although the fit is stellar, the synthetic material isn't the nicest against your skin.
Credit: Roland Mott


The thickness of this layer seems to fall in between a lightweight and mid-weight, though the warmth that it offers is comparable to other midweights that we tested. We were comfortable wearing this in cold temperatures but wouldn't suggest it for super cold conditions.

The tight weave paired with the synthetic fabric makes this by far the most wind resistant base layer that we tested. So it does really great as a stand-alone layer in cool temps and doesn't allow a chilly breeze to cut through it. We did notice, though, that synthetic fabrics feel cold on your skin in low temps whereas Merino layers always feel warm and cozy next to skin, even in freezing temps. It does a really great job at trapping heat once you're moving but the fabric feels cold against your skin when the temps are low and you're not moving.

arc'teryx phase ar crew ls base layer review - the arc'teryx phase ar was by far the most durable top we tested. it...
The Arc'teryx Phase AR was by far the most durable top we tested. It wasn't the most comfortable next to the skin and also not as breathable as merino, but bulletproof when it came to dragging it up climbs.
Credit: Roland Mott


The Phase AR has a low breathability score, but synthetic fabrics just don't breathe as well as natural fibers do. They tend to have a tighter knit or weave which typically allows them to be more wind resistant and significantly more durable.

For a synthetic fabric, this top breathes extremely well. It does a great job of wicking sweat and drying quickly but doesn't stack up when compared to Merino wool layers. Because it doesn't breathe as well, it's more likely to build up moisture on the inside in conditions where you are cranking out the body heat and because it's a synthetic material, it holds onto stink. If breathability is a top priority for you, we'd suggest a top that scored higher in that category, but if you need a top to have decent breathability but can benefit from the durability and warmth, then this is a good choice.

arc'teryx phase ar crew ls base layer review - the umph. as mike libecki calls it, pre-joy. this top didn't breathe...
The Umph. As Mike Libecki calls it, pre-joy. This top didn't breathe as good as our merino tops, and left us a little toasty in the full fall desert sun.
Credit: Roland Mott

Comfort and Fit

This top stands up to Arc'teryx reputation when it comes to quality of construction and sleek design. It is very purposefully designed with a full-length underarm gusset and thinner material in the armpit to help dump heat and improve breathability.

arc'teryx phase ar crew ls base layer review - the armpit gusset is made with the lighter phasic ls fabric to aid...
The armpit gusset is made with the lighter Phasic LS fabric to aid in breathability and provide a heat dump. Helpful, as this isn't the most breathable fabric compared to the merino layers.
Credit: Roland Mott

A sleek fitting torso, drop tail hem, with tapered sleeves give this a great fit. It fits snug against the body like a traditional base layer. The low profile neck collar is loose and comfortable. It may run a little tight thru the shoulders or biceps if you frequent the gym. The synthetic fabric is SUPER stretchy and paired with a nice length thru the torso and arms makes for excellent mobility. The stiffer feeling material is a bit limiting but stretchiness counteracts this well.

The unique fabric is not the coziest next to the skin. This was one the biggest downfalls in this layer for us. You just don't want to live in this baselayer day and night like you do in others that we tested, but the fit and quality of construction are superb.

arc'teryx phase ar crew ls base layer review - we noticed that even though the seams are flatlock we could feel...
We noticed that even though the seams are flatlock we could feel them against our skin in a slightly uncomfortable way.
Credit: Roland Mott

Drying Speed

As we've stated before, the drying speed of a base layer differs depending on whether it is being worn next to your skin or not. In the case of this layer, it dried quickly when next to skin but took significantly longer when flat drying.

This was one of the bottom three for dry times, which means there was only one layer that took longer to flat dry after being completely saturated and twice as long as the fastest drying tops. Don't let the poor flat dry time dissuade you because it actually dries quickly in situations where the fabric is wet from sweat. Still not as efficient as a Merino layer.

arc'teryx phase ar crew ls base layer review - the low profile neck is one of the many ways that this piece is...
The low profile neck is one of the many ways that this piece is obsessively crafted to deliver a great fit.
Credit: Roland Mott


Here's the shining star for the Arc'teryx Phase AR. This thing is bulletproof when it comes to base layers. Durability is generally a weak point of base layers but this thing is built tough. Dragging base layers up rough climbs and through canyons is almost always a quick path to destruction for a base layer but the Phase AR thrives. The tight-knit polyester is super tough, not easy to tear, resists abrasion, and is wind resistant compared to other base layers. This thing is like base layer armor, the downside is that it kind of feels like armor, not the comfiest directly on your skin.

This top is unphased by washing and drying cycles and doesn't lose shape or stretch out. A huge leg up on Merino layers in that sense. Our abrasion test in the lab blew holes straight through a few tops but just scratched the surface of this one. We gave this a top score for durability. If you beat the hell out of your gear, this is a great layer for you.

arc'teryx phase ar crew ls base layer review - this top is bulletproof, by far the most durable top that we tested...
This top is bulletproof, by far the most durable top that we tested. Here it is in its element, being drug up rough rock on a seldom seen or attempted aid climb.
Credit: Roland Mott

If you're looking for a top that can stand the test of time and is up for the task of surviving merciless and endless beatdowns, we suggest the Arc'teryx Phase AR.

Layering Ability

The obsessive design and fit of this top allow it to layer really well. The tight fit through the torso, tapered sleeves and smooth outer fabric make easy work of sliding layers over top of it without it bunching or pulling anywhere. Because of the stiffer fabric and tight fit, layering this over a t-shirt felt bulky and restrictive. Works great as a stand-alone layer, providing warmth in cool temperatures as well as some wind resistance.

arc'teryx phase ar crew ls base layer review - this top layered well, its slick outer material sliding easily...
This top layered well, its slick outer material sliding easily within layering systems. We didn't love wearing a shirt under it as it felt a bit restrictive.
Credit: Roland Mott

It does well sliding smoothly under a tight, sticky fleece mid layer like a Patagonia R1. It doesn't build up static electricity as easy as the Merino wool layers when layered with a fleece. Overall a smooth ability to layer but not versatile as far as being worn over top of anything. Because it is a stiffer feeling fabric, it can feel a bit bulky if layered under too many things.


This top sits right in the middle of the road for typical base layer prices. It's a great value for the quality and durability of the piece and quite possibly the most affordable Arc'teryx product we've ever seen. Again, if durability is the main concern but breathability and cozy factor are not, we think it's a good value.

arc'teryx phase ar crew ls base layer review - all smiles after dragging this top up squeeze chimneys and wide...
All smiles after dragging this top up squeeze chimneys and wide cracks to nab a seldom seen summit.
Credit: Roland Mott


A bulletproof base layer meant for being put to the test in some the roughest and toughest situations around. Warmth to get you through the cold seasons comfortably. Meticulous and detailed design and fit made with a durable and super stretchy synthetic fabric. Downsides are ok breathability and a not-so-cozy feeling next-to-skin.

Roland Mott
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