The Arc'teryx Kyanite inhabits the lightweight fleece niche and comes to represent. It's one of the warmer entries in the lightweight category but loses points for breathability and comfort.
While soft and stretchy, we wish this jacket had a longer hemline.
Performance Comparison
While it's no R1, Arc'teryx aficionados will be happy with this lightweight fleece.
Warmth
This jacket gets it's warming powers from the Polartec Power Stretch Pro fleece that comprises the entirety of the jacket. The slim fit of the Kyanite butts soft fleece right up against your skin, making it a thermally efficient mid-layer. The hood is form-fitting and designed to fit under a helmet and zips up to sit comfortably just above the chin.
This fleece features a soft, form fitting scuba style hood.
Comfort
Several features make this jacket a comfortable piece for layering. The elastic cuffs are perfect, tight enough that they stay in place when our testers put another layer on, but not so tight we couldn't comfortably pull up the sleeves. The handwarmer pockets are large and located high on the jacket, so they don't become inaccessible underneath a harness which our testers loved overall. Our one complaint about the Kyanite when it comes to comfort is that the hem is cut short when compared to the R1. Longer jackets provide more coverage for warmth and don't ride up over a climbing harness, making it difficult to grab gear on the fly.
Breathability
The best breathers among the fleeces have a waffle-like grid pattern, allowing air and moisture to move out through the little channels in the grid. Constructed with a uniform piece of fleece, the Kyanite has no breathable channels. Light and thin, this jacket breathes much better than heavier fleece, but not as well as Jackets designed with better breathability in mind.
This jacket layers easily under a light wind jacket.
Laying Ability
As mentioned earlier, the Kyanite is an excellent mid-layer. We often wore it between a t-shirt and an insulated jacket. While it doesn't have thumb loops, the elastic cuffs are tight enough that they don't ride up your arms when putting them through the sleeves of another jacket. This Jacket has a slim, athletic cut, so it doesn't bunch up and feel uncomfortable under other layers.
Weather Resistance
The Kyanite doesn't fare well when exposed to the elements. The wind cut right through to our tester during his bike commutes. There is no DWR treatment on this fleece, so water soaks through almost immediately, but underneath a wind or waterproof layer, the Kyanite offers a thin layer of cozy insulation, and it feels great against the skin, especially compared to a nylon rain jacket.
Weight
The Kyanite falls into the midweight fleece category tipping the scales at 13.4oz. Perfectly packable for the backcountry. However, our testers feel there are lighter weight fleeces out there that perform better.
Soft fleece dries quickly, but can't repel even light precip.
Style
This jacket is fully equipped for all-mountain adventures but looks fairly simple and low key, and our testers had no problem sporting it around town or around the house.
Value
If you want that dinosaur skeleton logo on your clothes, you gonna have to pay up. This fleece will set you back a hefty sum, but you'll get a good mid layer with the quality we've come to expect from Arc'teryx.
Small, soft zipper pulls reduce bulk and are better for layering.
Conclusion
The Arc'teryx Kyanite is a solid fleece that scores fairly in many of our metrics. It's a well-made jacket, but it lacks the never-take-it-off-even-to-sleep comfort of the Patagonia R1 Hoody, which remains the king of the breathable mid-layers.
