Arc'teryx Delta AR
Arc'teryx produced the Delta AR as part of their midlayer fleece lineup from the mid-2010s through approximately 2020, when the mainline version was discontinued. The Delta AR used Polartec Thermal Pro High Loft Grid fleece in a full-zip jacket design weighing approximately 300 grams. The "AR" designation means All Round, indicating versatility across different activities and conditions. The LEAF (Law Enforcement and Armed Forces) version remains available with Polartec Power Dry fleece. Made in various facilities, including El Salvador and China, depending on the production year.
Polartec Thermal Pro High Loft Grid Construction
The Polartec Thermal Pro High Loft Grid construction created an exceptional warmth-to-weight ratio that still impresses me years later. The grid pattern on the interior traps warm air in small pockets while allowing moisture to escape, which prevents the clammy feeling common with solid fleece. I've owned my Delta AR for over five years, and it remains my go-to midlayer for Colorado snowboarding trips when temperatures drop into the teens. The smooth outer face slides easily under shells without bunching, and the slim fit keeps bulk minimal while preserving range of motion.
How Does the Arc'teryx Delta AR Fit?
The slim fit runs true to Arc'teryx sizing. At just over 6 feet and 165 pounds, I wear a medium that allows a base layer underneath without restriction. The articulated patterning and gusseted underarms create natural movement whether I'm reaching overhead on climbs or twisting through trees on a snowboard. The longer cut tucks into pants to prevent cold air from creeping up during activity. The stretch-knit cuffs seal against wrists without bunching under gloves. For those who prefer a roomier fit for heavier base layers, sizing up works well since the fabric has minimal stretch.
Midlayer Warmth from 0 to 40 Degrees
As a midlayer, the Delta AR delivers. The High Loft Grid fleece provides substantial warmth for temperatures between 0 and 40 degrees when worn under a shell. I've used mine during single-digit snowboarding days with a Rho AR base layer and hardshell on top, and the combination kept me comfortable on chairlifts and during breaks. As a standalone layer, the Delta AR works for temperatures between 35 and 50 degrees during moderate activity. The fleece breathes well enough that I don't overheat on uphills, which makes it better than heavier options like the Strato Jacket for high-output activities.
Original Delta AR vs. 2024 Redesign
Arc'teryx completely redesigned the Delta line around 2024, replacing the Polartec Thermal Pro with a new octagonal hollow-core fleece construction. The current Delta Jacket (Model #X000009165) weighs 240 grams and uses a thinner, less warm fabric, according to user reviews. Many longtime Delta AR owners, myself included, prefer the discontinued version's warmth and feel. The new Delta prioritizes lightweight breathability over insulation, which makes it less suitable for cold conditions. If you want something similar to the original Delta AR's warmth, the Kyanite AR or Dallen Fleece offers comparable performance.
Resale Value and Current Alternatives
For users who want substantial fleece warmth in a midweight package, the discontinued Delta AR is available on resale sites for $80-150, depending on condition and colorway. The Polartec Thermal Pro construction has proven extremely durable in my experience, with no pilling or loss of loft after years of use. The current Patagonia R1 Air at $169 offers similar grid fleece performance with current availability. The Arc'teryx LEAF Delta AR remains in production for military and law enforcement channels, using Polartec Power Dry fleece with a balaclava hood option. Check Arc'teryx for current midlayer options.