Cocoons for the modern pioneer

A favorite of those looking for extra insulation, adventuring out on alpine backpacking trips, camping on porta-ledges, or embarking into less-hospitable environments.

Your Sleeping Bag's Backup System

You put a load of trust into your mummy bag. Sometimes it's the only thing that gets you through the night. But all the best gear and life-saving systems need a backup. That's what COCOON® MummyLiners™ are for.

25 products
  • MummyLiner™ Microfleece - Dark Petrol

    MummyLiner™ Microfleece - Dark Petrol

    $69.95 USD
    $69.95 USD

Choosing the Right Sleeping Bag Liner Fabric

With over 15 fabric options, the choice comes down to what your trip demands:

  • Silk sleeping bag liner: The classic. Featherweight, packs to the size of an apple, warm when it's cool and cool when it's warm. Our RipStop Silk adds durability for hard use.
  • Fleece sleeping bag liner: Our Microfleece models are the plush option for car camping, cabins, and cold-weather basecamps. Zippered sides for easy in and out.
  • Thermolite® Radiator®: If you want the warmest sleeping bag liner in the line, this is it. Hollow-core fibers trap air and push your bag's rating meaningfully lower.
  • Egyptian Cotton and Cotton Flannel: Breathable, soft, budget-friendly. Ideal for hostels, huts, and summer nights.
  • COOLMAX®: Moisture-wicking for humid climates where the goal is staying dry, not warm.
  • Merino Wool: Odor-resistant and warm even when damp. Multi-day trips without a wash.
  • Insect Shield®: Built-in permethrin treatment for regions where the bugs are the real problem.

Why a Liner Belongs in Every Pack

  • Adds warmth without adding a heavier bag.
  • Protects your investment — liners wash easily, sleeping bags don't.
  • Doubles as standalone bedding in warm weather, huts, and hostels.
  • Packs small — most compress smaller than a water bottle.
  • Feels better than nylon against your skin at 3 a.m.

FAQs

How much warmth does a sleeping bag liner add?

Up to roughly 16 degrees, depending on fabric. Thermolite® Radiator® delivers the most.

Which liner is warmest? 

The MummyLiner™ Radiator® Thermolite®, followed by Microfleece and Merino Wool.

Can I use a liner on its own? 

Yes. Silk and cotton liners work well as standalone bedding in hostels, huts, and warm-weather camps.

How do I wash it? 

Machine wash cool on gentle for most fabrics; silk prefers hand washing. Air dry.