Merino Wool Sleeping Bag Liner

Comfort for the Miles Ahead

After a long day outside, settle into a soft layer of premium Merino. The Glacial Gear Merino Wool Sleeping Bag Liner is made from 100% New Zealand ZQ Merino wool and sewn in small batches in Taylors, South Carolina. Its breathable fabric and natural stretch bring next-to-skin comfort to your sleeping bag or quilt.

A washable layer between you and your sleep system helps keep trail dirt and body oils off your sleeping bag. Merino’s natural odor resistance makes it especially useful for repeated nights at camp and trips between laundry stops.

Why Merino Wool?

• Soft against skin: Premium 18.9-micron New Zealand ZQ Merino wool.
• Breathable comfort: Merino helps manage moisture and temperature as you rest.
• Naturally odor-resistant: A useful quality for multi-day trips.
• Room to move: Horizontal stretch gives the mummy-shaped liner flexibility as you change sleeping positions.
• A washable barrier: Helps keep your sleeping bag or quilt cleaner.

The liner adds a layer of comfort to your existing sleep system. Warmth depends on your sleeping bag, pad, clothing, conditions, and how you sleep; we do not assign this liner a specific temperature boost.

At Camp and Beyond

Use it inside your sleeping bag, beneath a quilt, or as a personal sleep layer in hostels and on your travels. In suitably warm conditions, it can provide light coverage on its own. Choose your full sleep system for the overnight conditions you expect.

Choose Your Size

• Small: Fits up to 5′6″ (168 cm). Approximately 68 in long; 14.2 oz (403 g).
• Medium: Fits up to 6′0″ (183 cm). Approximately 74 in long; 15.2 oz (431 g).
• Large: Fits up to 6′6″ (198 cm). Approximately 80 in long; 16.0 oz (454 g).

All sizes have a 56 in (142 cm) shoulder circumference. Measurements and weights are approximate; slight variations are possible.

Compare liner sizes in our gear guide →

The first prototype

Patrick French, known on trail as “Dosu Kinuta,” is the third person to thru-hike all 11 U.S. National Scenic Trails. He’s also a returning survivalist on Discovery’s Naked and Afraid, including Castaways and Last One Standing.

Patrick and I became good friends while hiking the Ocean to Lake Trail together. Later that year, in May 2022, he spent five days at our home between adventures.

During that visit, I saw the sleeping bag liner he’d been carrying since 2015. After seven years of use, it was in tatters. Seeing it gave me an idea—and within a day, I had designed and made the first Glacial Gear sleeping bag liner prototype.

Patrick headed out with it right away, bound for the Ice Age Trail and the North Country Trail. This photo captures the day we held up that first prototype, before it ever saw a mile of trail.

3,000 miles later

That first prototype went on to travel more than 3,000 miles with Patrick, including his 2022 Ice Age Trail thru-hike and sections of the North Country Trail. His verdict:

“One thing I like about a bag liner is that when I'm dirty and sweaty, it acts as a barrier between that filth and your sleeping bag or quilt — which are typically difficult to clean and dry.”

“Given the quality and the benefits, it's worth the weight year round.”

— Patrick French, “Dosu Kinuta”

Specifications

Fabric: 100% New Zealand ZQ Merino wool
Fiber diameter: 18.9 micron
Fabric weight: 200 GSM
Shape: Mummy
Shoulder circumference: 56 in (142 cm), all sizes
Packed size — Medium only: Approximately 9 × 3½ × 3½ in (22.9 × 8.9 × 8.9 cm).

Care

Machine wash on a delicate cycle. Lay flat to dry or tumble dry on low heat. Let the liner dry completely before storing it, and keep it protected when not in use.

Origin

Made in Taylors, South Carolina in small batches using premium Merino wool fabric imported from New Zealand.

Sleeping Bag Liner Questions

How much warmth does it add?

It provides an additional fabric layer and next-to-skin comfort, but we do not specify a tested temperature increase. Use the temperature rating of your sleeping bag or quilt, a suitable sleeping pad, and the expected weather to plan your sleep system.

Can I use it without a sleeping bag?

It can be used as light coverage in suitably warm conditions, including indoor travel stays. It does not have a standalone sleeping-bag temperature rating. Bring insulation appropriate to your trip rather than relying on the liner for cold nights.

Which size should I choose?

Start with your height: Small fits up to 5′6″, Medium up to 6′0″, and Large up to 6′6″. All three sizes have the same 56 in shoulder circumference, so choosing a longer size adds length rather than shoulder width. If you are near a height limit or unsure about fit, contact us for sizing help.

How small does it pack?

The Medium packs to approximately 9 × 3½ × 3½ in. Packed dimensions depend on how it is folded and compressed. This measurement applies to the Medium; we have not listed packed measurements for Small or Large.

Can I use it with a down sleeping bag or a quilt?

Yes. Use it as a breathable layer between your body and the sleeping bag or quilt. It helps keep the sleep system cleaner, but it is not a waterproof or vapor-barrier liner and does not guarantee that down will stay dry.

Is this the same liner sold by Zpacks?

These are separate products with different fabric specifications and care instructions. This Glacial Gear liner uses 100% New Zealand ZQ Merino wool at 200 GSM and 18.9 micron. The Gostwyck Ultrafine Merino liner sold by Zpacks, which we manufacture for them, uses a different Merino fabric. Follow the sizing, weight, and care information for the specific liner you purchase.

SHEEPishly Superior.