Arc'teryx Kyanite AR Half Zip

The Arc'teryx Kyanite AR Half Zip weighs 290 grams and uses Polartec Power Stretch Pro fleece to deliver exceptional warmth with compression-resistant insulation. The 53% polyester, 38% nylon, and 9% elastane blend provides four-way stretch that moves with the body. The half-zip design with chin guard allows ventilation control while the slim fit enables layering under shells. Priced at $140, this sits between lightweight base layers and heavier midlayers. Available in Black, Utopia, and Cryptochrome. I wear this for cold-weather hiking and snowboarding because the Power Stretch Pro fleece delivers more warmth than standard fleece while maintaining breathability.

Slim Fit That Layers Without Bulk

The slim fit sits closer than relaxed options like the Dallen Fleece Pullover while providing more stretch than the Kyanite AR Tech Wool Crew. The four-way stretch fabric moves with me during dynamic activity without binding. I wear a medium, and the Kyanite AR fits comfortably over base layers with room for movement.

The articulated patterning follows body contours during reaching and bending. The Tanica stretch fabric binds the cuffs, hem, and collar without creating pressure points. The half-zip opens far enough for ventilation without exposing base layers.

The slim fit allows this to layer under shells without creating bulk. I can wear this under my hardshell during snowboarding or under an insulated jacket during cold hikes. The stretchy material compresses easily.

Why Polartec Power Stretch Pro Outperforms Regular Fleece

Polartec Power Stretch Pro provides compression-resistant warmth that maintains loft when compressed under a shell jacket. Regular fleece loses insulation when compressed, but Power Stretch Pro's construction preserves warmth even when layered. This makes it more effective as a midlayer than standard fleece.

The four-way stretch provides mobility that regular fleece cannot match. The 9% elastane content allows the fabric to stretch in all directions while recovering shape. This is critical during technical activity where arm movement and torso rotation require fabric that moves with the body.

The moisture-wicking performance exceeds standard fleece. The polyester-nylon blend pulls sweat away from skin and dries quickly during high-output activity. I can hike hard uphill and the Kyanite AR manages moisture without becoming saturated.

Best Between 20 and 40 Degrees

Yes, this delivers exceptional warmth for 20°F to 40°F conditions. The Polartec Power Stretch Pro fleece provides more insulation than expected from a 290-gram piece. The compression-resistant construction maintains warmth even when layered under shells.

For extremely cold conditions below 20°F, I layer this under an insulated jacket. For moderate cold between 30°F and 45°F, I wear this as an outer layer with base layers. The half-zip allows temperature regulation.

The brushed interior feels warm against skin while the smooth exterior reduces friction. The two zippered hand pockets with brushed mesh interior provide additional warmth for hands. Similar wind resistance to the Sniper Zip but with more stretch.

How Does the Arc'teryx Kyanite AR Compare to Competitors?

Patagonia's R1 TechFace Hoody at $169 uses Polartec Power Grid fleece with weather-resistant face fabric. The R1 TechFace offers more wind resistance but less stretch. The Patagonia weighs more and costs $29 more.

Outdoor Research's Vigor Half Zip at $120 uses Polartec Power Stretch fleece for $20 less. The OR provides similar stretch but uses standard Power Stretch rather than Power Stretch Pro, offering less compression-resistant warmth.

The Arc'teryx justifies the $140 price with Power Stretch Pro fabric, articulated patterning, and slim fit optimized for layering under shells.

Technical Performance Over Casual Comfort

For technical cold-weather activities, yes. The Polartec Power Stretch Pro fleece delivers exceptional warmth with four-way stretch that enables unrestricted movement. The compression-resistant construction maintains insulation when layered. The slim fit layers effectively without bulk.

For casual everyday wear, no. You're paying for technical performance rather than casual comfort. If you need a fleece for around town, the Dallen or Kyanite AR Crew provides similar comfort.

Arc'teryx prices this at $140 in Black, Utopia, and Cryptochrome colorways. Material is 53% polyester, 38% nylon, 9% elastane Polartec Power Stretch Pro. Weight is 290 grams. Slim fit with articulated patterning. Half-zip with chin guard. Best for cold-weather technical activity in 20-40°F.

Current availability at Arc'teryx.