The world's most in-depth and scientific reviews of outdoor gear

Arc'teryx Sigma SL Anorak Pullover - Women's Review

This lightweight and streamlined pullover is a fabulously durable layer that breathes like a dream and dries lightning fast.
Editors' Choice Award
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Price:  $179 List | $179.00 at REI
Compare prices at 4 resellers
Pros:  Highly breathable, quick-drying, harness and helmet compatible, stowable hood, durable
Cons:  Not very warm, only one pocket
Manufacturer:   Arc'teryx
By Penney Garrett ⋅ Senior Review Editor  ⋅  May 22, 2019
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81
OVERALL
SCORE


RANKED
#1 of 15
  • Weather Protection - 30% 7
  • Breathability - 30% 9
  • Mobility - 25% 8
  • Weight - 10% 9
  • Versatility - 5% 7

Our Verdict

The Arc'teryx Sigma SL Anorak Pullover breezed through our testing criteria like a pro, solidifying its place at the front of the pack and securing an Editors' Choice award. We found this layer to be our favorite softshell for warm weather activities like rock climbing, hiking, trail running, and cycling. The material is durable and protective without feeling overly stiff or scratchy on bare skin. Providing more-than-adequate wind and water resistance, it dries super fast if you get caught in a spring rain shower or are dripping sweat. The deep front zip allows for easy ventilation, the cut offers great mobility, and the features are just right without being overkill. If you want something to take on all your warm-weather activities, we highly recommend the Sigma.

Keep in mind that this style of softshell is unlined and won't provide a whole lot of warmth. If you'd rather have something that leans more in that direction, check out our pick for cooler temps and other Editors' Choice, the Arc'teryx Gamma MX Hoody. If you want to stay lightweight but would prefer to spend less moolah, we have two great Best Buy options: the mega thin Outdoor Research Whirlwind Pullover and the stretchy Rab Borealis.


Compare to Similar Products

Our Analysis and Test Results

If you're looking for a layer to breathe, move, and become like a second skin on your next big adventure, this one might be just the ticket.

Performance Comparison


Optimized for climbing  the Sigma Anorak is a great technical layer to consider owning.
Optimized for climbing, the Sigma Anorak is a great technical layer to consider owning.

Weather Protection


While not meant for serious cold or stormy weather, the Sigma still provides admirable wind and water protection for warmer weather activities.


We felt quite protected in this pullover despite how thin and light it is. Its wind resistance is apparent and it repels water impressively well. On top of that, when the Sigma does get wet, it dries almost supernaturally fast. With the breathable nature of the fabric, this is also a great piece to use as a sun layer when you don't want to get scorched. And while not meant for super cold temps, the slim cut means it's easy to layer under something more substantial if needed.

This pullover is fantastic for those spring and fall days where it's chilly and windy one moment and blazing hot from the sun the next.
This pullover is fantastic for those spring and fall days where it's chilly and windy one moment and blazing hot from the sun the next.

Breathability


Among the best in our review, the Sigma is a highly breathable layer suitable for cardio-intensive activities and warmer days.



This pullover offers a really impressive trifecta of breathability, protection, and quick-drying material. Whether it's super sunny or you're working up a sweat (or both!) you won't feel stifled and wet spots will dry fast. But, magically, when a cool breeze rolls in you'll also feel protected. It's kind of amazing that one layer can handle so many different scenarios so well. Climbing in the spring it was especially easy to appreciate the Sigma because it can handle the quick changes of temperature, sun, wind, and body temp with ease.

The Sigma is incredibly breathable and the deep front zip allows for even more ventilation when necessary.
The Sigma is incredibly breathable and the deep front zip allows for even more ventilation when necessary.

Mobility


Another area of excellence for the Sigma Anorak. Created with a lightweight four-way stretch material that is both highly abrasion-resistant and easy to move in, you'll be happy in this layer no matter what your activity of choice is.


When handling this pullover the material doesn't feel overly stretchy. But once on the body, it moves fluidly and gracefully. The slim cut means it stays close to the body and out of the way without being constrictive. Special inserts in the hemline keep everything tucked neatly below a harness. The hood has a button to roll it up and stow it away if you don't want the extra material hanging behind you. The only reason we didn't award the Sigma a higher score is because we felt a bit of snugness across the shoulders when pulling it on and off. This piece is created primarily for climbers but they tend to be bigger and broader across that area. Despite this, we feel it runs true to size. It's just something to be aware of if your upper back muscles are mega swole and you're ordering online — you might want to size up.

Stretchy and expertly tailored  the Sigma is a delight to climb and move in.
Stretchy and expertly tailored, the Sigma is a delight to climb and move in.

Weight


The Sigma has an "SL" designation which stands for "superlight" — and at just 9.5 ounces for a size medium, it certainly is!


Arc'teryx says the emphasis for this jacket is on light weight and packability. That coupled with its durability make it a great alpine layer. Even if space is at a premium and your bag is full, there's probably room to stuff this layer in a nook or cranny. Our guess is that you'll be glad you did.

The expertly-designed Sigma is one of the lightest in our review and also one of the more feature-rich.
The expertly-designed Sigma is one of the lightest in our review and also one of the more feature-rich.

Versatility


With excellent features and fantastic breathability, mobility, and weather, resistance, this savvy pullover is pretty darn versatile.


While the Sigma probably isn't what you'll grab for date night or a backcountry ski excursion, it's quite versatile within its wheelhouse. It breathes superbly and yet still provides an excellent wind and water barrier. You can use the hood or stow it away. It has a slim, athletic cut, yet still moves and stretches with ease. The special Hemlock inserts keep it under a harness or backpack strap but are also removable. You can zip it up to the chin or vent down to almost the navel. All in all, this is a layer with a lot of uses and a great addition to a comprehensive outdoor wardrobe.

Here you can see the removable Hemlock inserts - soft foam pieces that keep the hemline securely below your harness even when stretching  reaching  and grunting your way to the top of a project.
Here you can see the removable Hemlock inserts - soft foam pieces that keep the hemline securely below your harness even when stretching, reaching, and grunting your way to the top of a project.

Best Application


It's pretty clear that the Sigma SL is designed with climbers in mind. The weight, mobility, breathability, and features all make it ideal for alpine objectives and swing season cragging. That being said, this is also a stellar layer to consider for long hikes, trail running, and cycling. If you move, sweat, and go big in the warmer months of the year, this pullover will very likely make you smile.

Climbing with the Sigma Anorak is a no-brainer  but it's also well suited to many other swing season outings. Anything that requires movement and inspires a high heart rate is a great fit for this pullover.
Climbing with the Sigma Anorak is a no-brainer, but it's also well suited to many other swing season outings. Anything that requires movement and inspires a high heart rate is a great fit for this pullover.

Value


While not cheap, this piece is still in the affordable range of technical layers. Considering how high-performing and feature-rich it is, the price seems well worth what you get. If you need something to keep you protected from wind and rock that will dry fast and breathe with your body, the Sigma is definitely worth its weight in abrasion-resistant material (and more — it doesn't weigh very much!)

Conclusion


The Sigma SL Anorak is a lightweight technical softshell geared toward alpine rock climbers. But don't walk away if that isn't what you do — this well-designed pullover has a place alongside many other activities as well. It's incredibly breathable, stretchy, weather resistant for its weight, and crazy quick-drying. If you canyoneer, run, hike, or bike in non-winter months, this is a smart layer to own and an easy one to appreciate.

From climbing to walking a pup  this pullover is grand.
From climbing to walking a pup, this pullover is grand.


Penney Garrett