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Best sleeping bag liners 2022: for extra warmth, cleanliness and comfort

Collage of the best sleeping bag liners
(Image credit: Future)

If you’re new to camping, investing in one of the best sleeping bag liners might not be an obvious priority. The best sleeping bag and best camping tent you can afford are top of your list, sure. But believe us, a good sleeping bag liner is that crucial bit of kit you never knew you should own. 

You don’t need a liner to camp, of course, but you’re definitely going to be more comfortable with one. These packable, lightweight sleeping bag inners are a very useful addition to your outdoor sleeping system. Popped inside your regular sleeping bag, they protect your expensive, insulated bag from rips, dirt and sweat, and are easier to stick in the wash regularly than a difficult-to-dry, insulated sleeping bag. This makes them ideal for using on multi-day hikes, festivals and other adventures where you may not be washing much. 

The best sleeping bag liners also add warmth, allowing you to use a sleeping bag in temperatures a few degrees cooler than you could comfortably tolerate without one. We also like liners used in conjunction with a camping quilt, as they’ll stop you slipping and sliding about on your sleeping pad

On really hot nights, you can even chuck off your sleeping bag altogether and use a breathable liner on its own. If you’re not camping, a sleeping bag liner can still be a very useful bit of kit for backpacking, mountain refuge hikes and hostel-hopping, offering a more hygienic cocoon to sleep in if you’re not completely sure how clean the sheets are.

Best silk sleeping bag liners

Rab Ascent Sleeping Bag Liner

(Image credit: Rab)

Rab Ascent Silk Liner

This lightweight little silk number is a quality all-rounder for keen hikers

Specifications

Weight: 130g / 4.6oz
Pack size: 18cm x 10cm / 7in x 4in
Material: Silk
Shape: Mummy
Colors: Slate
Compatibility: A great all-rounder liner for all seasons

Reasons to buy

+
Lightweight
+
Soft, warm, silk 
+
Good mummy/rectangular hybrid shape

Reasons to avoid

-
Expensive

Silk is a bit of a wonder material for liners, as it traps in heat quickly but still breathes well and has a great warmth-to-weight ratio. 

This Ascent liner tips the scales at just 130g, so it’ll suit even the most weight-conscious backpacker, as well as working for travelling and traditional camping adventures. Silk feels pleasingly soft against the skin and even has antimicrobial properties, so it’ll help keep your sleeping bag fresh for longer. 

Rab reckon this liner is mummy-shaped, but on test we found that this tapered bag sat somewhere between rectangular and mummy shapes. It’d be a good choice if you want just one liner to fit into all your sleeping bags without having too much extra material bunched up in any design you choose to pair it with. 

This quality liner should last for years, and Rab also offer a repair service that extends the life of your kit. 

Best synthetic sleeping bag liners

Therm-A-Rest sleeping bag liner

(Image credit: Therm-A-Rest)

Therm-A-Rest Sleep Liner

A warm and versatile all-rounder available in three sizes

Specifications

Weight: 320g / 11oz
Pack size: 23cm x 12cm / 9in x 5in
Material: Polyester
Shape: Mummy
Colors: Grey
Compatibility: Welcome warmth for slimmer campers on cool nights

Reasons to buy

+
Noticeably warm
+
Good zip
+
Brushed material

Reasons to avoid

-
On the slim side

If you’re shopping for your first sleeping liner for cool nights, you won’t go wrong with Therm-a-Rest’s Sleep Liner design. This well-made all-rounder ticked all our boxes on test – it adds warmth, it’s easily machine-washable and it has a good three-quarter zip to make getting in and out of the bag quick and easy come bedtime. 

Three sizes are available, so this is a good choice if you need a shorter or longer line than most. Therm-a-Rest reckon their design adds three degrees centigrade of warmth, and we did find that it noticeably trapped in more heat than using a sleeping bag alone. 

We liked adding it to our sleep system on crisp, chilly nights, but reckon you’d overheat fast on hot summer nights unless you used the liner alone and partially unzipped it. While this bag is made with polyester, it’s got a brushed finish to the material that feels soft and not plasticky to touch. 

Snugpak Paratex sleeping bag liner

(Image credit: Snugpak)

Snugpak Paratex Liner

A liner that also works well as a standalone bag for hammock camping

Specifications

Weight: 200g / 7oz
Pack size: 15cm x 9cm / 6in x 3.5in
Material: Paratex
Shape: Rectangular
Colors: Black / Olive / Desert Tan
Compatibility: Protect your sleeping bag in winter, or use it alone in summer

Reasons to buy

+
Water-resistant
+
Windproof 
+
Wicks away sweat

Reasons to avoid

-
Doesn’t add much warmth

If you’ve got a great three- or four-season sleeping bag that keeps you cosy at most temperatures, your priority when adding a sleeping bag liner is likely to be more about keeping that bag in great condition rather than about adding significant warmth. 

Snugpak’s Paratex liner is all about protection – it’s designed to wick moisture away from the body, keeping you dry without affecting your bag’s lining, and is also easy to wash and dry on the go. 

We found this liner doubled up nicely as a standalone lightweight sleeping bag, too – the outer material is water-resistant and windproof, so it’s ideal for warm summer nights when you’re bivvying, or in a camping hammock and you don’t need much warmth but could do with some protection just in case the weather does take a turn while you’re asleep.

Fjern Slumra sleeping bag liner

(Image credit: Fjern)

Fjern Slumra Liner

A simple polyester liner to protect your sleeping bag on the move

Specifications

Weight: 340g / 12oz
Pack size: 18cm x 8cm / 7in x 3in
Material: Recycled polyester
Shape: Mummy
Colors: Navy / Burnt Orange
Compatibility: Pack this polyester liner for shoulder season camping or for hostelling

Reasons to buy

+
Recycled materials
+
Small pack size
+
Easy to wash

Reasons to avoid

-
Not very breathable

This bright liner (we tested the orange version) is a good choice for cooler camping conditions in spring and fall, or for using as an extra layer during winter stays in hostels or mountain huts, when its polyester material traps in warmth nicely. In hot or humid weather the polyester isn’t breathable enough to be comfortable – switch to cotton or silk instead. 

This liner also does a great job of protecting your bag from dirt and sweat, and once you’re back home, it comes out of the washing machine as good as new, and dries fast.  

Most of the sleeping bag liners we’ve come across aren’t recycled, but this one is made with 100 per cent recycled polyester, so it’s a more sustainable choice than most. 

At 340g and with a tiny pack size, the Slumra is a good portable option for backpacking trips, hut-to-hut hikes and camping trips where you’re packing light.

Best sleeping bag liners for winter

Sea To Summit Thermolite Reactor sleeping bag liner

(Image credit: Sea to Summit)

Sea To Summit Thermolite Reactor Liner

Add warmth without weight to your sleep system with this fleecy liner

Specifications

Weight: 248g / 9oz
Pack size: 15cm x 11cm / 6in x 4in
Material: Thermolite
Shape: Mummy
Colors: Black / Yellow
Compatibility: Ideal for adding warmth to wild camps without significant weight

Reasons to buy

+
Reliable added warmth
+
Fleecy feel
+
Mid-weight

Reasons to avoid

-
Too warm for summer weather

A lot of sleeping bag liners talk big talk about how much warmth they can add to your sleep system, but the Thermolite Reactor was one of few that we found that, on test, significantly improved how much heat was trapped inside our sleeping bag. 

The brand’s bestselling design is made of lightweight Thermolite fabric, which traps in body heat fast. If you couple it with your favorite down sleeping bag, you’ll have a guaranteed toasty sleep system in most temperatures. 

Thermolite is a synthetic fabric that feels rather like fleece to touch but is lighter in weight and more packable. As a result, you get winter-ready warmth without too much bulk and – at 248g – barely any added weight. The mummy shape fits nicely into tapered sleeping bags, too. 

Need something that offers a bigger hit of heat for cold winter nights? The Reactor Extreme (opens in new tab), ($70 / £60) is an even warmer version claiming to offer a boost of 15°C.

Snugpak Fleece Sleeping Bag Liner

(Image credit: Snugpak)

Snugpak Fleece Liner

A heavy but pleasingly soft fleece liner that’s ideal for bitter winter nights

Specifications

Weight: 1kg / 2lb 3.3oz
Pack size: 25cm x 18cm / 10in x 7in
Material: Fleece
Shape: Mummy
Color: Olive green
Compatibility: Cosy comfort for winter campers

Reasons to buy

+
Winter-capable warmth
+
Quick-drying
+
Soft and comfy

Reasons to avoid

-
Heavy
-
Not recycled

If warmth and comfort is top of your sleeping bag liner shopping list, try Snugpak’s luxuriously soft offering for size. 

This fleece liner is deliciously cosy to climb into after a long day’s hiking, traps in body heat quickly and is still breathable if you do get hot in the night. We also love the full-length zip for easy access (unlike some liners we tested, which you have to really wiggle about to clamber into). 

While this is a warm liner, there is a weight penalty – at 1kg, this design weighs in at more than double some lightweight sleeping bags. But if you camp in all seasons, fancy giving winter glamping a go or want to add warmth to your chilly camper van, this fleece is well worth the weight and bulk. 

On test we found the reassuringly thick and soft fleece also made this a nice standalone sleeping bag for summer nights when you still want a bit of weight over you. It’s just a pity the fleece isn’t made from recycled plastic. 

Best budget sleeping bag liners

Decathlon Polyester Sleeping Bag Liner

(Image credit: Decathlon)

Decathlon Polyester Liner

A cheap liner that packs into any rucksack and offers good protection

Specifications

Weight: 260g / 9oz
Pack size: 20cm x 10cm / 8in x 4in
Material: Polyester
Shape: Rectangular
Color: Grey
Compatibility: Casual camping and backpacking in shoulder seasons

Reasons to buy

+
Affordable
+
Easy to wash and dry
+
Lightweight

Reasons to avoid

-
Not breathable

Decathlon’s pocket-friendly liner is ideal for casual camping, school or scout adventures, or if you just want to try out a sleeping bag liner without investing in something too pricy. 

This simple liner fits nicely into rectangular sleeping bags, offers good protection for their inner material and is easily removed and cleaned. It also adds some warmth, so it’s a good choice for spring and fall nights outdoors, but the downside is that polyester isn’t very breathable – you may sweat and overheat on hot nights. 

This little liner weighs a respectably light 260g and packs down small enough to fit nicely into daysacks, so we like using it for hut to hut hiking and shorter wild camping weekends in cooler weather where the priority is keeping a sleeping bag clean and in good condition. Decathlon call this a, “great value-for-money liner,” and it’s hard to argue with that. 

Mountain Warehouse sleeping bag liner

(Image credit: Mountain Warehouse)

Mountain Warehouse Liner

A well-priced and soft-to-touch cotton liner that works well for hot weather

Specifications

Weight: 360g / 12.7oz
Pack size: 25cm x 10cm / 10in x 4in
Material: Polycotton
Shape: Rectangular
Color: Pale blue
Compatibility: Ideal for hot summer camps and international travel

Reasons to buy

+
Pillow pocket 
+
Breathable material
+
Cool on hot nights

Reasons to avoid

-
Snug fit 
-
Thin material 

Summer is a lovely time to camp outdoors – until you overheat in your stuffy three-season sleeping bag. On hot nights under canvas, swap to this lightweight and breathable liner. 

Polycotton is a mix of cotton and polyester (here, it’s 35 per cent cotton, 65 per cent polyester) that offers a good balance between the softness and moisture-wicking properties of cotton and the added durability of polyester. 

This simple but quite thin-feeling rectangular bag is a good choice for tropical travelling, festivals and more casual summer camps, and washes and dries easily when you’re back home from your adventures. 

A sewn-in pillow pocket is great for keeping a camping pillow in place all night if you tend to toss and turn in your sleeping bag. Mountain Warehouse’s design is quite snug to slide into, so taller or bigger campers may want to pick a liner with a more generous width.

Best sleeping bag liners
Sleeping bag linerRRPWeightMaterial
Rab Ascent Silk Liner$70 (US) / £60 (UK)130g / 4.6ozSilk
Therm-A-Rest Sleep Liner$45 (US) / £55 (UK)320g / 11ozPolyester
Snugpak Paratex Liner$39 (US) / £32 (UK)200g / 7ozParatex
Fjern Slumra Liner$38 (US) / £30 (UK)340g / 12ozRecycled polyester
Sea To Summit Thermolite Reactor Liner$63 (US) / £50 (UK)248g / 9ozThermolite
Snugpak Fleece Liner$60 (US) / £38 (UK)1kg / 2lb 3.3ozFleece
Decathlon Polyester Liner$12.99 (US) / £7.99 (UK)260g / 9ozPolyester
Mountain Warehouse Liner$25 (US) / £19.99 (UK)360g / 12.7ozPolycotton

How we test the best sleeping bag liners

The above sleeping bag liners were all tested on camping trips and camper van adventures in a variety of temperatures and climatic conditions.

How to choose a sleeping bag liner

Not all liners are created equally. You’ll find plenty of different materials and shapes on the market, but our handy guide below will help you pinpoint the best sleeping bag liner for you. Whichever design you choose, liners tend to be compact and affordable (our recommended liners start from just $13 / £8), so we reckon they’re a bit of a must for camping adventures – but consider the following factors…

Weight and size

Have a think about where and how you plan to use your new sleeping bag liner before you invest in a shiny new one. 

First up, pack size: if you’re going wild camping or usually only camp for a weekend at a time, small, lightweight models that pack into a backpack or a bike pannier are your best bet. If your idea of a good camping holiday is full bells and whistles in a campsite or a glamping tent, you can pick a heavier, warmer but bulkier liner. Likewise, if you want a warm fleece liner for winter, you may need to pick a liner with a larger pack size but which offers that much-needed added heat. 

Second, weight: some silk liners weigh a smidge above 100g, so they’re ideal for weight-watching fastpackers. Thick fleece liners can weigh 1kg – more than some sleeping bags – so they’re better for car campers and winter weekend camps. 

Make a decision on what weight suits your setup before you shop – or you could even invest in a few different liners.

Best sleeping bag liner

A liner is easier to clean (and dry) than a sleeping bag (Image credit: Getty Images)

Material

You’ll find liners on the market made from all kinds of material. The priciest is silk, which is brilliant for camping as it’s lightweight but still offers lovely warmth and feels great against the skin. Silk also offers the best protection from mosquitoes and other biting nasties too, so it’s a good choice for nights in hot tropical countries. 

Cotton and polycotton are ideal for summer weather, as they are highly breathable, and brushed cotton also feels rather like your favorite duvet would, so it’s nice if you’re sick of the feel of your plasticky sleeping bag – but remember: cotton offers no thermal protection if it gets wet and can be dangerous in alpine scenarios as a result. 

Polyester is affordable and does trap in warmth, but doesn’t breathe well at all, so it’s best used in spring and fall rather than hot or humid conditions. 

Winter campers should pick a warm fleece liner – it’s often the bulkiest material on offer but traps in warmth quickly while still being breathable, soft and quick to dry if you pop it in the wash.

Shape

Liners come in rectangular or tapered ‘mummy’ shapes, just like sleeping bags. Mummy shapes offer less range of movement but are usually warmer, while rectangular bags and liners offer more room to toss and turn but tend to trap in less heat. Shopping for the right-sized sleeping bag liner is easy: just pick a liner that matches the shape of your favorite sleeping bag. 

An award-winning travel and outdoors journalist, presenter and blogger, Sian regularly writes for The Independent, Evening Standard, BBC Countryfile, Coast, Outdoor Enthusiast and Sunday Times Travel. Life as a hiking, camping, wild-swimming adventure-writer has taken her around the world, exploring Bolivian jungles, kayaking in Greenland, diving with turtles in Australia, climbing mountains in Africa and, in Thailand, learning the hard way that peeing on a jellyfish sting doesn’t help. Her blog, thegirloutdoors.co.uk, champions accessible adventures.