Arc'teryx Sigma SL Anorak Pullover - Women's Review
Cons: Not very warm, no stow-away pocket for clipping to your harness, cuffs stretch out with heavy use
Our Analysis and Test Results
It is no wonder that the Sigma SL Anorak stole the show. This dope layer balances wind-protection with breathability like a dream. It is feather-weight with just enough features, comfortable and moveable but also abrasion-resistant and durable, and it looks good to boot.
Being an active softshell, the Sigma SL is not designed for winter conditions or seriously inclement weather. That said, it provides considerable wind protection and water resistance in a light drizzle.
The Sigma offers great weather protection for an active softshell, being as wind-resistant as they come (without being wind-proof). When coupled with a lightweight fleece, like the Patagonia R1, it is sufficiently warm into fairly low temps — as long as you are moving. In our water-resistance tests, the Sigma was in the middle of the pack. This means that while the Sigma is not an ideal layer to keep you dry in a deluge, it provides some water resistance in light rain or dry snow. As an alpine climbing layer, the Sigma is great for days when meteorologists predict low-levels of precip. Even on those days, we always bring a lightweight rain jacket like the Outdoor Research Helium II for unexpected weather emergencies (especially in the unpredictable Rocky Mountains). Rest assured, if you do get caught in a storm, the Sigma dries almost supernaturally fast. With the breathable nature of the fabric, (a tightly woven proprietary material called Aequora Airperm), this is also a great piece to use as a sun layer when you don't want to get scorched. Finally, while the Sigma is not meant for super cold temps, the slim cut means it's easy to layer under or over something more substantial if needed.
The Sigma SL breathes well during cardio-intensive activities and warmer days, and if you need more ventilation, it features a deep front zipper for extra air-flow. While some folks will find it suitable for things like trail running on cooler days, it's better suited for slightly slower-paced activities like climbing or hiking.
This pullover offers an 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 overly stifled, and wet spots will dry fast. Magically, when a crisp breeze rolls in, you'll also feel protected. It's kind of amazing that one layer can handle so many different scenarios so well. This is why we love the Sigma for climbing almost year-round (if you're lucky enough to have access to sunny crags in the winter). It handles quick changes in sun, wind, and body temp.
Mobility is really where the Sigma shines. It is made out of a lightweight four-way stretch material that is highly abrasion-resistant and easy to move in, you'll be happy in this layer whether you're having a spontaneous backcountry dance party or swimming up desert cracks.
At first touch, 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. Really though, the most innovative aspect of this pullover is the proprietary "Hemlock" (foam) inserts in the hemline — these rad little buddies keep the jacket locked in place under your harness. Never again will you have to wrestle with your jacket to hide climber's crack from your belay partner. Phew. Beyond this, 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 the Sigma did not earn a higher score in this category is that the stretchy nylon in the cuffs stretched a bit too much with heavy usage. This is not a deal-breaker, but the sleeves did feel noticeably loose around the wrists when reaching for high handholds after a couple months of hard use. That said, it's still an incredibly mobile and cozy softshell that we love for protecting our skin in off-widths and chimneys.
The Sigma has an "SL" designation, which stands for "super light" — at just 9.5 ounces for a size small, it certainly is!
This Sigma is lightweight and incredibly packable, though it would be even more packable with a stow-away pocket for clipping on to your harness. This minor drawback aside, when you couple the Sigma's featherweight with incredible durability, you get a fantastic alpine climbing layer. Even when your pack is stuffed to the brim with climbing gear, there's always a fragment of space to cram this jacket. You'll be glad you did.
With excellent features and fantastic breathability, mobility, and weather-resistance, this savvy pullover is pretty darn versatile.
The Sigma shines in fair but breezy weather, or when in a light summer rain. It handles wind like a boss, making it an incredible wind layer for multi-pitch and alpine climbing, hiking, light mountaineering, or peak-bagging. When used with a light fleece, the Sigma can handle breezy and cooler days in the spring and fall, as well as alpine starts in the summer. It is the most durable jacket in our review, making it an ideal layer for abrasion resistance in granite chimneys and off-width. It is fitted, attractive, has a spacious helmet-compatible hood, and with the foam inserts in the hem, it resists jacket-creep while climbing. The hem-cinch is somewhat complicated to undo, but with the Hemlock inserts, it is unnecessary when under a harness. You can zip the Sigma up to the chin for extra warmth or vent it down to your belly-button for extra air-flow. If you're looking for a three-season, wind-resistant jacket for rock climbing of all persuasions, then this little gem might be right for you.
While the Sigma certainly is not one of the least expensive jackets in our review, it is decently affordable. If you're looking for an ultra-durable, lightweight, fast-drying, and wind-resistant climbing layer, this jacket certainly checks all those boxes and more. Considering how high-performing and feature-rich it is, the price seems well worth what you get. If you're down to foot the bill, you will be pleased you did, as this jacket will prove its worth nearly every time you head out to climb.
The Sigma SL Anorak is a lightweight technical softshell geared toward alpine rock climbers. Don't let that turn you away if that isn't what you do — this well-designed pullover is a fantastic layer for a number of other activities too. It's incredibly breathable, stretchy, durable, weather-resistant for its weight, and crazy quick-drying. Bottom-line, the Sigma is a fantastic layer for all manner of outdoor pursuits from hiking, running, and bike commuting to peak-bagging, fair-weather backpacking, and canyoneering. We think you'll be as psyched as we were to give this Editors' Choice Winner a try.
— Mary Witlacil and Penney Garrett