Arc'teryx Kyanite vs. Delta: Which one is better?

The Arc'teryx Kyanite and Delta are two of the brand's most popular fleece jackets, but they are built for very different purposes. The Kyanite is a warmer, exceptionally durable, and comfortable all-around fleece ideal for layering in cold conditions or as a standalone jacket, while the Delta is a highly breathable, technical grid fleece designed for high-output activities where managing sweat is the top priority. The choice comes down to warmth and durability versus technical breathability.

Here’s a complete look at these two fleeces from Arc'teryx to help you decide which one belongs in your layering system.

Arc'teryx Kyanite Fleece

The Arc'teryx Kyanite is the quintessential do-it-all fleece. Known for its exceptional comfort, four-way stretch, and impressive durability, it serves as a reliable mid-layer for a wide range of activities. Its clean aesthetic and plush interior make it just as suitable for everyday casual wear as for climbing or hiking.

• What it is: A versatile, warm, and highly durable fleece designed as a mid-layer or standalone jacket for various activities.
• Key features: Exceptional four-way stretch for mobility, a durable nylon face that resists pilling and abrasion, a soft, brushed interior for warmth, and an air-permeable design that helps regulate temperature.
• Price: Around $180-$200
• Materials/Construction: Made from Polartec® Power Stretch® Pro, which combines a highly durable nylon face with a soft, moisture-wicking polyester interior.
• Sizing/Fit: A trim, athletic fit that layers easily under a shell jacket without restricting movement. It fits true to size for most users.
• Pros: Extremely comfortable and stretchy, highly durable fabric resists abrasion, performs well as both a mid-layer and standalone piece, and versatile enough for technical and casual use.
• Cons: Less breathable than the Delta during intense activity, heavier and less packable, and can be too warm for mild conditions or high-output pursuits.

This fleece is perfect for anyone needing a fleece that blends technical performance with everyday comfort and can withstand the abuse of climbing or backcountry use.

Shop this product: arcteryx.com/us/en/shop/mens/kyanite-hoody

Arc'teryx Delta Fleece

The Arc'teryx Delta is a highly specialized piece of active insulation purposefully designed for thermoregulation during high-output activities. Its gridded fleece construction provides warmth while prioritizing breathability and moisture wicking, making it a go-to for ski touring, climbing, and running in cool weather.

• What it is: A lightweight, highly air-permeable technical grid fleece engineered to provide warmth during high-exertion activities.
• Key features: A gridded interior fabric pattern that enhances breathability and wicking performance, a lightweight and highly packable design, and a minimalist construction for functional layering.
• Price: Around $160-$200
• Materials/Construction: Made primarily from Polartec® Power Dry® high-efficiency grid fleece, which has excellent moisture-wicking and quick-drying properties.
• Sizing/Fit: A next-to-skin, trim fit designed to maximize moisture transfer and layer efficiently under other shells without any bulk. It stays close to the body.
• Pros: Exceptional breathability and moisture management, very lightweight and packable, dries incredibly fast, and excels during stop-and-go mountain sports.
• Cons: Provides less warmth than the Kyanite, the gridded fabric is less durable and more prone to snagging, and its technical aesthetic makes it less versatile for casual city wear.

This is the fleece for the mountain athlete who needs a layering piece that breathes and wicks sweat away during intense aerobic effort.

Shop this product: arcteryx.com/us/en/shop/mens/delta-jacket

Arc'teryx Kyanite vs. Delta Comparison

Materials, Warmth &, Breathability

The core difference between the Kyanite and the Delta lies in their materials. The Kyanite uses Polartec® Power Stretch® Pro, a dense, stretchy fabric with a durable nylon face and a brushed interior. This makes it significantly warmer, more wind-resistant, and far more durable than the Delta. It feels cozier and offers more protection when worn as a standalone jacket.

In contrast, the Delta’s Polartec® Power Dry® grid fleece is engineered for maximum airflow. The open grid channels let heat and moisture escape rapidly, preventing you from overheating during strenuous climbs or runs. While it provides some insulation, its main job is to keep you dry from the inside out. It offers very little wind resistance and is less warm than the Kyanite when you are stationary.

Fit &, Layering

Both fleeces are designed with a trim, athletic fit typical of Arc'teryx gear, but they serve different layering functions. The Kyanite has a more relaxed, but still athletic, fit. Its incredible four-way stretch ensures it never restricts movement, making it an excellent mid-layer for skiing or climbing under a hardshell. Because of its smoother face fabric, layers slide over it effortlessly.

The Delta has a much slimmer, next-to-skin fit. This is intentional, as it helps the gridded material make contact with your skin or base layer to wick moisture away effectively. It’s designed to be a highly efficient component in a technical layering system, where its minimal bulk allows it to disappear under other layers.

Versatility &, Best Use Case

The Kyanite is the clear winner in versatility. Its blend of warmth, comfort, and durability - combined with a clean, minimalist design - makes it a true workhorse. You can wear it climbing, skiing, hiking, to the office, or running errands around town. Its tough outer face holds up to abrasion from rock faces and backpack straps, giving it a much wider range of uses.

The Delta is a specialist's tool. It truly shines during high-intensity activities in the mountains. Think backcountry skiing, ice climbing, trail running, or fast-and-light mountaineering. While you can wear it casually, its primary purpose is technical performance, where its breathability is a critical advantage. It is not as warm or durable for everyday needs.

Which One Should You Choose?

Both fleeces are excellent, but they cater to very different performance needs and user preferences.

Choose the Arc'teryx Kyanite if:

• You need a versatile, all-around fleece for both technical and casual use.
• Prioritizing warmth, comfort, and durability is more important than maximum breathability.
• You plan to use it for rock climbing or activities with high abrasion risk.
• You want a single fleece that can function as a warm mid-layer and a stylish standalone jacket.

Choose the Arc'teryx Delta if:

• Your primary need is breathability and moisture management during high-output activities like running or ski touring.
• You run hot and often find traditional fleece jackets too warm.
• You need a lightweight and highly packable fleece for your backcountry missions.
• You value technical performance above all else in your mid-layer.

Frequently Asked Questions

What’s the main difference between the Arc'teryx Kyanite and Delta?

The main difference is their intended function. The Kyanite is a versatile, durable, and warm all-purpose fleece for general use and cold-weather layering. The Delta is a technical grid fleece designed for maximum breathability and moisture wicking during intense aerobic activity.

Which fleece is warmer, the Kyanite or the Delta?

The Kyanite is significantly warmer than the Delta due to its thicker, denser Polartec® Power Stretch® Pro fabric. The Delta is designed to breathe, so it provides less insulation.

Which is better for high-output activities like ski touring?

The Delta is much better for high-output activities. Its gridded structure is far more breathable, allowing it to efficiently vent heat and manage sweat, which is critical for staying comfortable and dry during hard efforts.

Is the Kyanite durable enough for climbing?

Yes, the Kyanite is an excellent choice for climbing. Its Polartec® Power Stretch® Pro material has a nylon face that is highly resistant to abrasion from rock, ropes, and packs, making it far more durable than the Delta fleece.

Does the Arc'teryx Delta fleece pill?

The grid fleece fabric of the Delta can be more susceptible to pilling and snagging than the Kyanite, especially under abrasive backpack straps over long-term use. The Kyanite’s smooth face fabric is highly resistant to pilling.

How should they fit? Should I size up or down?

Both fleeces generally fit true to size with an athletic trim fit. The Delta has a closer, next-to-skin fit. There’s no need to size up or down unless you are between sizes, in that case, consider how you will primarily layer it. Stick to your normal size for the intended performance fit.

Can I wear the Delta or Kyanite as a standalone jacket?

The Kyanite works very well as a standalone jacket in cool, dry conditions due to its thicker fabric and moderate wind resistance. The Delta offers very little protection from the wind and is less warm, so it functions best as a layering piece under a shell.

Which fleece is more comfortable for casual wear?

The Kyanite is generally considered more comfortable for casual, everyday wear. Its soft, plush interior and durable, sleek exterior make it a cozy and stylish option for around town.