Best Sleeping Bag Liner 2018

Sleeping bag liners are a must-have for any backpacking trip.

A good liner will keep your sleeping bag clean, prolonging it’s life. Depending on the material used, it can also increase the temperature rating of your bag by an extra 5-15F, keeping you warm on those chilly nights.

Ever since I found myself in a "luxury hotel" in Delhi 25 years ago, I've never traveled without one.

Quick Look

Sea to Summit Thermolite Reactor Fleece - for added warmth and comfort

Sea to Summit Thermolite Reactor Extreme - for added warmth and bit less bulk

Dimples Excel & Friendly Swede - Basic, low cost liners to keep your sleeping bag clean.

Sleeping Bag Liners that add Warmth - Reviews

Overall a great choice if you are wanting to add a bit of extra warmth without much bulk.

A popular liner made from soft fabric the Thermolite Reactor claims to boost the warmth rating of your sleeping bag.

I found that this certainly added a little extra warmth but I wouldn't rely on it to add much.


Sizing: Length: 210cm, Width: 90cm Lightweight at 348g

What We Like

  • Lightweight and compressible, can be stored in it's own compression sack or left inside the sleeping bag.
  • 80g/m2 of Thermolite adds warmth to the sleeping bag
  • Thermolite hollow core fiber has a good warmth-to-weight ratio keeping you warmer without adding bulk
  • Breathable fabric wicks moisture away from your body on warmer nights
  • Mummy shape with footbox to fit well into your sleeping bag without excessive material
  • Drawcord hood for a comfortable fit around your head and neck


What We Don't Like

  • Material is thin and porous and feels a bit flimsy
  • Claims that it will add 8C to your sleeping bag's warmth rating. This is difficult to measure and I wouldn't rely on it
  • Can be difficult to get into if you are a larger frame

Similar to the Thermolite Reactor, but a tiny bit heavier, this sleeping bag liner will add additional warmth to your sleeping bag.


The fabric is lightweight and stretchy. I found this one made a big difference to my comfort when camping in front of a glacier in Crater Camp, Kilimanjaro.


However, I would not rely on it to increase the warmth-rating of a sub-standard sleeping bag.


Sizing: Length: 183cm Width: 90cm (Note that this stretches)

Weight: 399g

What We Like

  • Lightweight and compressible, the tapered design reduces weight and bulk
  • 110g/m2 of thermolite adds warmth to the sleeping bag
  • Thermolite hollow core fiber is stretchy so that you can move around comfortably
  • Breathable to wick moisture away from your body
  • Mummy shape with a foot box maximizes thermal efficiency and it fits well into a sleeping bag
  • Drawcord hood preventing heat loss around your head and neck area

What We Don't Like

  • Material can feel a bit clingy due to the stretch in the fabric
  • Claims that it adds up to 15C to the temperature rating of your sleeping bag. These figures are very hard to measure, I would not rely on it.

A more heavy-duty fleece liner that will really boost the warmth-rating of your sleeping bag.


If you have a 15F sleeping bag and want to be sure of staying warm in the mountains, then this could be your choice.


The lovely brushed fabric is super-soft to the touch and when I tried it out I was too warm! 


Ideal if you sleep very cold or are less confident about the warmth rating of your sleeping bag. 

You can also use it on it’s own as a light sleeping bag when conditions are warmer. And it’s lovely for curling up on the sofa on a cold winter’s night!

Sizing: Length: 200cm Width: 70cm

Weight: 420g (higher than lighter fabric, but still low for a technical fleece liner)

What We Like

  • Mummy shape reduces bulk and maximizes thermal efficiency
  • Definitely increases the warmth rating of your sleeping bag
  • Smaller than most fleece liners, packs down small
  • Brushed fabric is soft and comfortable against your skin
  • Quarter zip makes it very easy to get in and out of
  • Panelled hood for extra comfort and preventing heat loss around your head
  • So warm and cosy that it can be used alone on warmer nights

What We Don't Like

  • Larger and bulkier than other liners, maybe difficult on a backpacking trip (just get a warmer sleeping bag!)
  • Cost - if you haven’t already bought your sleeping bag, you might like to consider using the money to buy a better sleeping bag!

Sleeping Bag Liners for Hygiene

Soft to the touch and lightweight, silk sleeping bag liners are a popular choice.


A bit less durable than cotton or synthetic, silk can potentially add a little warmth to your sleeping bag.


Great if you like a bit of luxury on your adventures!

Sizing: 241 x 90 x 56cm

What We Like

  • ​Silk is "ripstop" making it durable
  • Extremely light and packs down very small - you’ll hardly notice it’s there!
  • Quick drying, can be machine or hand washed
  • Super-soft to the touch, gives you a lovely comfortable night
  • Tapered mummy shape with footbox to fit nicely into your sleeping bag
  • Drawstring hood allows you to adjust it around your head/neck - perfect for nights in hostels or other places of dubious cleanliness
  • Can possibly add around 5F to the warmth rating of your sleeping bag - though I wouldn't rely on this

What We Don't Like

  • Cost: silk is more expensive than cotton or polycotton
  • No side openings, even with the wide-top opening sometimes it can be difficult to get in and out of at night
  • Sizing might be snug if you are very tall or well-built
  • The stitching looks a bit flimsy even though the specs state "double-stitching"

A basic, no-frills polyester sleeping bag liner at a nice price point. 


The satin texture is comfortable, cool and very lightweight.


This is worth considering if you just want to use it as a barrier between yourself and your bag, but don't want to sacrifice weight in your pack.


It won’t add much in terms of warmth, but it's a solid choice for keeping your bag hygienic.

What We Like

  • ​Cost: a lot cheaper than silk
  • Very soft to the touch with a satin texture
  • Roomy enough for restless or side sleepers
  • Side opening with velcro closure allows easy access in and out of the liner
  • Attached pillow slip - great for staying in dodgy hostels
  • Folds up small and light taking up very little weight in your luggage
  • Quick drying for easy cleaning on the trail

What We Don't Like

  • ​Seems a bit flimsy
  • Velcro closure can feel a bit scratchy

A comfortable, synthetic stretchy sleeping bag liner that will take up little room in your luggage.


Soft to the touch, the stretchy material does not restrict your movement during the night.


I found it a bit too "clingy" however, which is a personal preference, I liked the non-stretch liners better.

What We Like

  • ​Cost: cheaper than silk and more durable
  • Stretch knit polycotton fiber that is soft to the touch
  • Easy to get in and out of for late night calls of nature
  • Antimicrobial treatment keeps your sleeping bag and the liner fresh and hygenic on multi-day hikes
  • Comes in different shapes - mummy with hood and foot box, rectangular and “traveller” which also has a pocket for a pillow
  • Packs down small and light in it’s own stuff sack
  • Quick drying and machine washable

What We Don't Like

  • ​The stretchy material can get caught up if you are a restless sleeper - I found it a bit "clingy"
  • Could be a bit uncomfortable if you are a very large build, even though it stretches

A basic sleeping bag liner made of synthetic fabric with a silky finish.


This one won’t add much warmth to your sleeping bag, but at this price point it’s a good choice if you just want to keep your sleeping bag clean.


Lightweight and packs down very small, you'll barely notice it in your luggage.

What We Like

  • Satin polyester is breathable, soft and silky to the touch
  • Roomy design preventing you from getting tangled up in it
  • Side opening with velcro closure allows you to easily get in and out of the liner
  • Packs down very small and light so won’t take up valuable weight and space
  • Quick drying makes keeping it clean a breeze

What We Don't Like

  • I wish they wouldn't use velcro closures - they can get scratchy
  • Whilst roomy, it's probably not suitable if you are over 6' tall

My first sleeping bag liner was cotton. I really hated the feeling of the nylon inner inside the sleeping bag.


A basic, everyday liner the cotton will protect your bag.


If you really hate man-made fabrics, and don’t want to pay out for silk, then a simple cotton liner could be a good choice.


Don’t expect it to add warmth, and try not to get it wet, as it will take ages to dry!

What We Like

  • ​Cost this is a basic liner at a budget price
  • Partial opening on the side allowing you to get in and out more easily
  • Durable, lightweight cotton fabric for a comfortable night’s sleep

What We Don't Like

  • Slow to dry - if this is important, then you'd do better to opt for silk or synthetic.

Why Use a Sleeping Bag Liner?

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    Protecting the sleeping bag: You’ve paid for a good sleeping bag. Heading off up Kilimanjaro or to the backcountry is a dusty, sandy experience. The fine sand and dust will eventually get into the insulation of the sleeping bag and degrade it. Using a sleeping bag liner will prolong the life of your sleeping bag.
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    Hygiene: Keeps your sleeping bag clean, preventing oils from your skin and sweat from damaging the lining material of the bag. It's much easier to launder a liner than a sleeping bag! 
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    Additional warmth: a good sleeping bag liner can improve the temperature rating of your sleeping bag - some manufacturers make very optimistic claims of up to 25 degrees. I am skeptical of that but a good Thermolite liner can certainly add 5-15F to your bag's rating
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    Comfort: sometimes in the inner linings of sleeping bags can feel a bit clammy and the nylon/polyester doesn't suit everyone. Having a liner in your choice of fabric ensures that what comes into contact with your skin is comfortable for you.
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    If you are renting a sleeping bag, or staying in a hostel lacking in hygeine, then the liner will provide a useful barrier between you and any dirt left behind by the previous occupant!
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    On warmer nights, you can sleep in the liner instead of your sleeping bag, preventing you from overheating.

Different Types of Sleeping Bag Liners

Liners come in a variety of materials:

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    Silk or silk-blend: these are the most lightweight and compressible. They provide good insulation, improving the warmth of your bag slightly. Silk is absorbent and breathable keeping you dry and your sleeping bag protected.
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    Cotton: a bit more bulky than silk but at the very least a cotton liner will be absorbent and protect your sleeping bag. Cotton is durable but slow to dry if it gets wet.
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    Fleece or Microfleece: these liners are the warmest, adding up to 12F to your sleeping bag’s rating. If you have a 3-season sleeping bag, one of these can increase the rating to 4-season. Quick drying, absorbent and breathable, these tend to be more bulky and heavier.
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    Synthetic (eg CoolMax): Very lightweight, moisture-wicking and breathable, these will add a little warmth and are very good for humid conditions.
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    Insulated (eg Thermolite): These sleeping bag liners are made from hollow core fiber insulation and are the warmest of all liners, adding 15-20F to your sleeping bag’s warmth. Quick drying, they are also a bit larger and bulkier. Ideal if warmth is your goal.

Shape

Good sleeping bag liners come in a variety of shapes. Mummy-shape to fit your sleeping bag, rectangular shaped for sleeping in hostels or traditional sleeping bags.

Others are made of a stretchy material so that you don’t get tangled up in it. Some have zips or velcro closures or are simply a tube.

Some liners will have a space for a pillow which is mostly for use in hostels and hotels of dubious cleanliness. Tube shapes can be a bit difficult to get in and out of for calls of nature during the night.

Conclusion

If you are unsure of whether your sleeping bag is going to be warm enough then the Sea to Summit Thermolite Reactor Fleece will add warmth and comfort.

If you don't want the added bulk of the fleece one, but still want some warmth then the Sea to Summit Thermolite Reactor Extreme is well worth a look.

For a basic liner to keep your sleeping bag clean, then the Dimples Excel or the Friendly Swede. They won't add much in the way of warmth, but are well-priced and will do the job.

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