Jacks R Better · Liners
Jacks R Better Polartec Alpha Direct Quilt Liner
Specs
| Temp rating | 15°F |
|---|---|
| Packed size | 10" |
Description
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.
Sewn-in foot box
This is not a flat rectangle. The liner is 72" long × 55" wide, with a 15" circular foot box sewn in at the bottom, so your feet tuck into a closed end.
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
| Model | Weight | Standalone Comfort | As a Liner Adds |
|---|---|---|---|
| Alpha Direct 90 | 8 oz | ~60°F | 5–10°F |
| Alpha Trail 90* | 7 oz | ~60°F | 5–10°F |
| Alpha Direct 120 | 12 oz | ~50°F | 10–15°F |
*Alpha Trail 90 features two-way stretch and packs even smaller than the Alpha Direct 90. It is more fragile than standard Alpha Direct 90 — it sacrifices durability and stretch for weight savings.
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.