Polartec Alpha Direct Quilt Liner

Polartec Alpha Direct does something most insulation can’t — it actively regulates temperature instead of just trapping heat. Built with the same technology trusted by mountain guides and ultralight thru-hikers, it breathes when you run warm and insulates when you don’t — so you stop waking up sweaty at 2 am. Whether you’re pushing your sleeping bag into shoulder-season territory or heading out on a warm-weather overnight with nothing but this, it’s the layer that earns its weight.

What makes it different

Polartec Alpha Direct skips the shell fabric entirely — the insulation is the surface, designed to sit directly against your skin. That means less bulk, faster drying, and a next-to-skin softness you won’t find in a standard sleeping bag liner. Unlike other fabrics that go clammy when temperatures and humidity climb, Alpha Direct stays soft and dry against your skin — no sticking, no cling, no matter how muggy it gets. Use it as a standalone summer quilt on warm nights, a versatile camping liner for any sleep system, or a packable backpacking liner that pulls its weight on thru-hikes, weekend trips, and nights at home alike. Trail Tested. Couch Approved.

How to use it

• As a sleeping bag liner: Adds 5–15°F to any 3-season bag, extending your system deep into shoulder season
• As a quilt liner: Pairs with any backpacking quilt to extend its warmth range without the bulk of a heavier bag
• As a summer quilt: Standalone warmth rated to 50–60°F — ultralight, packable, ready for warm-weather camping
• For backpacking and thru-hiking: At 7–12 oz, it earns every gram without adding bulk to your kit

Choose your weight

*Alpha Trail 90 features two-way stretch and packs even smaller than the Alpha Direct 90.

Specs

• Material: Polartec Alpha Direct Fleece
• Dimensions: 72" long × 55" wide
• Foot box: 15" circular, sewn-in
• Packed size: 10" long × 4" diameter cylinder
• Made in Pennsylvania 🇺🇸

Want to push your liner into shoulder-season territory? Add the Windproof Shell — 2.9 oz of Argon 67 that blocks wind and light moisture, extends your effective warmth range by several degrees, and packs down to nothing.

Want that warmth-and-wind combo in one sewn quilt? The Wind Gap Alpha sews Alpha Direct to an Ion 1.1 windproof shell — a windproof liner, 50°F top quilt, or hammock underquilt in a single piece.

⚠️ These sell out as fast as we make them. In stock? It ships the same or next business day. Sold out? Order anyway — every restock we’ve had has arrived already spoken for by backorders, so the queue is the only reliable way to get one. We’ll sew yours and ship it in about 2–4 weeks.