Enhance your sleep system with Sea to Summit's sleeping bag liners

A sleeping bag liner is the next-to-skin layer in your sleep system. It can help retain warmth in your sleeping bag when conditions are cold, or conversely, in warm and humid environments, it adeptly manages moisture, ensuring a more comfortable sleep experience. Beyond its functional benefits, a sleeping bag liner also acts as a protective barrier, preserving the cleanliness of your sleeping bag and extending its overall lifespan. Seasoned adventurers consider it an essential component of their gear, recognizing that using a sleeping bag without a liner is simply not an option.

Sea to Summit has long been the market leader in technical sleeping bag liners; for 2024, the range has been enhanced with new fabrics, more technical shapes and functional details that allow the liners to better integrate with our 2024 Sleeping Bags.

Introducing our 2024 Sleeping Bag Liners

The majority of Sea to Summit’s technical liners are made of soft, knitted fabrics that stretch and move with you as you turn in your sleep. Increasing sleep comfort is a key reason for using a liner, whether it serves as a thermal or moisture-management layer inside a sleeping bag, or a hygienic sleep sheet in a hostel or budget hotel. Unlike sleeping bags (particularly down bags), liners can be washed easily, and dry quickly – throw your technical liner into the washing machine with your base layers after a backpacking trip or wash your travel liner in a hostel sink. All 2024 Sea to Summit liners feature HEIQ Fresh, a bio-based amino sugar polymer. The treatment absorbs compounds that cause odors and then releases them when the liner is washed. This keeps your liner odor-free when you are on the trail or traveling.

Let’s get you acquainted with the different liner families.

Thermal Boost Liners

Use a Thermal Boost Liner whenever you need to add warmth to a sleeping bag – in every kind of adventure, from lightweight backpacking to car camping. Sea to Summit’s thermal liners use premium Thermolite fabrics and enhanced technologies to retain as much warmth as possible.

Includes: Reactor, Reactor Extreme, Reactor Fleece

Moisture Management Liners

A moisture management liner wicks moisture from your skin and spreads it out quickly over a broad area where it can dissipate easily. It’s like your favourite wicking base layer but in a full-body version. Sea to Summit’s Moisture Management Liners are available in both budget-friendly and premium versions, in mummy, rectangular and Traveller versions – ideal for applications from lightweight backpacking to hostel dorms to airport floors.

Includes: Comfort Blend, Breeze

Lightweight Liners

If your kind of adventure involves counting grams, yet you still would like the enhanced comfort and hygiene in a sleeping bag that a liner brings, the Sea to Summit Silk Blend liner will be your first choice.

Includes: Silk Blend

How to Find Your Ideal Sleeping Bag Liner

Owning your journey starts with the right gear. So, how do you choose the right sleeping bag liner? Here are a few elements to consider.

Like to add warmth?

The Reactor and Reactor Extreme Liners are constructed using hollow-core Thermolite fibres, a blend of Thermolite Pro and recycled Thermolite EcoMade. The hollow-cores and knitted structure trap insulating air, and ceramic pigments integrated into the fibres absorb and radiate infra-red energy – all of which provide you with extra warmth inside your sleeping bag. 2024 Reactors have a closer-fitting hood for a greater thermal boost.

If you would like to add even more thermal performance, the Reactor Fleece Liner is built from a grid-pattern fleece fabric made of 60% Thermolite® EcoMade and 40% polyester yarns. Take one with you on your coldest winter adventures, or use it as a summer stand-alone sleeping bag (especially in sandy or damp conditions where you may not want to use a down sleeping bag).

Want to manage moisture?

Moisture management is the technical name given to fabrics that wick perspiration away from your skin and spread it out over a larger area where it can dissipate. Sea to Summit offers two types of moisture management liners to help you sleep more comfortably in warm, humid conditions: the more travel-oriented Comfort Blend liners and the more premium backpacking/travel Breeze liners.

Comfort Blend liners are made of 70% Coolmax and 30% Tencel Lyocell and are available in a Rectangular or a Traveller shape with a built-in pillowslip.

Breeze liners are constructed from 70% Coolmax EcoMade (made of 100% recycled yarns) and 30% Tencell Lyocell. The Breeze is available in a Mummy and a Traveller shape.

Both liners are soft, stretchy and incredibly comfortable. If you have ever felt clammy in a sleeping bag or suffered through a humid night in a budget hotel room, one of these liners is for you.

How do the liners integrate with the 2024 sleeping bags?

Several of the 2024 Sea to Summit sleeping bags utilize the Free-Flow system, which consists of a secondary short side zipper and a footbox zipper in addition to the full-length primary side zipper.

The 2024 Mummy-shaped technical liners now have openings in the shoulders and a drawcord in the foot section, which harmonise perfectly with the Free-Flow zippers. Reach your arms out through the openings/sleeping bag zippers and enjoy a cup of coffee in your tent. Or simply use the shoulder openings for additional ventilation to fine-tune your temperature perfectly. You can even open the base drawcord and ‘hitch up’ the liner – making middle-of-the-night bathroom breaks much simpler…

Of course, you don’t need a Sea to Summit sleeping bag to experience an increase in comfort by using one of our liners (but just think how much more versatile your sleep system would be if you did pair your liner with a Free-Flow bag…)

What else to consider in your sleeping bag liner?

Liner silhouettes

The mummy shape is generally the most thermally efficient, especially with the new technical fitted hoods for 2024. Mummy-shaped liners are also lighter and more packable than rectangular or Traveller-shaped liners – which is why they are the first choice for backpackers.

The Traveller shape imitates the rectangular design of your bed, making these liners ideal for hostels, hotels and anywhere you want to be assured that you will find a clean, hygienic sleep environment when you go to sleep. The pillowslip keeps your pillow securely in place.

Premium, sustainable materials

Our liners are sustainably crafted using a variety of recycled Thermolite® and Coolmax® fibres.

However, true sustainability goes beyond simply using recycled materials. The most sustainable product is one that does not need to be replaced. Using a liner prevents oils, sweat and fine-grain sand from damaging a sleeping bag. And it significantly reduces the frequency with which a sleeping bag – even a well cared for sleeping bag – needs to be washed, which will also extend its life.

Repowering for the journey

Tomorrow’s adventure begins with a great night’s sleep. Build a sleep system using the right liner, sleeping bag, sleeping mat and pillow and wake well-rested and ready to take on whatever’s next.