A sleeping bag liner does exactly what it sounds like - it lines your sleeping bag. It is designed to be worn as a barrier between you and the actual sleeping bag itself. Think of a sleeping bag liner as a bed sheet for the backcountry.
We tested the best sleeping bag liners on the market today. Read on to see which model is best for you and get some buying advice.
Table of Contents
Best Sleeping Bag Liners
The best sleeping bag liners are:
- Best Overall Sleeping Bag Liner: WESTERN MOUNTAINEERING - TIOGA
- Best Synthetic Sleeping Bag Liner: COCOON - COOLMAX
- Best Budget Sleeping Bag Liner: ALPS MOUNTAINEERING MICROFIBER MUMMY
- Warmest Sleeping Bag Liner: SEA TO SUMMIT - REACTOR THERMOLITE
|1. Western Mountaineering - Tioga||3.6 oz||100% Silk||$88||2.25 x 4 in||9/10|
|2. Cocoon - Silk Mummy||4.4 oz||Silk||$70||5.7 x 2.4 in||9/10|
|3. Cocoon - CoolMax||9 oz||CoolMax Polyester||$50||3.5 x 7 in||8/10|
|4. Alps Mountaineering Microfiber Mummy||11 oz||Polyester||$25||7.5 x 3 in||8/10|
|5. Big Agnes Sleeping Bag Liner - Cotton||14.5 oz||100% Cotton||$45||3 x 6 in||8/10|
|6. Therma-rest Synergy Sleeping Liner||12.1 oz||Polyester||$45||N/A||8/10|
|7. Sea to Summit - Reactor Thermolite||8.7 oz||Thermolite Polyester||$63||5.8 x 4 in||8/10|
|8. Sea to Summit - Insect Shield CoolMax||8.7 oz||CoolMax Polyester||$65||6 x 4.5 in||8/10|
- Weight: 3.6 oz (0.225 lbs)
- Material: 100% Silk
- Packed Size: 2.25 x 4 in
If we were writing a definition of an ultralight sleeping bag liner the Western Mountaineering Tioga would be it. It weighs less than half of most liners on our list while providing similar warmth.
We love silk for its natural odor-resistance. And we love that it packs down tiny, the Tioga has the smallest packed size on our list. We find silk super comfortable too. This is the most expensive liner on our list but, at 3.6 oz it is a great value for ultralight backpackers making it our best overall sleeping bag liner.
✅ Great all-around option
❌ Slightly less warmth than similar models
- Weight: 9.0 oz (0.56 lbs)
- Material: CoolMax Polyester
- Packed Size: 3.5 x 7 in
The Cocoon Coolmax is made of a very comfortable material similar to the Sea to Summit Insect Shield liner. We love that the Cocoon Coolmax costs about $15 less. You do sacrifice the Insect Shield and a bit of warmth though.
We like this option for warm sleepers. We found it to be breathable and wicks away sweat. This sleeping bag liner scores high in every category making it our top pick for a synthetic liner.
✅ Easy-open design
❌ Less comfortable
- Weight: 11 oz (0.69 lbs)
- Material: Polyester
- Packed Size: 7.5 x 3 in
The Alps Mountaineering Microfiber Mummy is made of synthetic microfiber material, like a travel towel. We found it to be a little rough at first but after a few washes it softens up. Unlike most liners, this liner folds open on the right side, rather than a top entry. We think this is a much easier option for getting in and out of. That is of course unless your sleeping bag opens on the left side.
Weight-wise we don’t love that this is one of the heavier options we reviewed. Overall, we love it for a great budget option, it’s the least expensive liner on our list. We recommend it for those looking to try out a sleeping bag liner with a low-risk price tag.
✅ Serious warmth-to-weight ratio
- Weight: 8.7 oz (0.54 lbs)
- Material: Thermolite Polyester
- Packed Size: 5.8 x 4 in
We love the Sea to Summit Reactor Thermolite liner for its excellent warmth-to-weight ratio. In fact, this is the warmest sleeping bag liner on our list, adding up to 14 degrees to a sleeping system. And, it weighs less than many comparable liners. With this warmth, we love it as a light blanket on its own or in colder backpacking conditions when serious warmth is needed.
Our biggest gripe is that this extra warmth comes with extra bulk, ranking near the bottom of our list. But for those needing warmth above all else this is our top pick for the warmest sleeping bag liner. We’d also recommend checking out the Reactor PLUS model for even more warmth.
The Other Noteworthy Models
- Weight: 4.4 oz (0.275 lbs)
- Material: Silk
- Packed Size: 5.7 x 2.4 in
The Cocoon Silk Mummy is a popular silk bag liner and we find it to be another stellar choice for ultralight backpacking. Like other ultralight liners, it is basic but excels in its simplicity. The silk is soft on the skin and doesn’t hold odors as much as other materials.
We like that it is less expensive than the Western Mountaineering Tioga. The trade-off is it weighs 0.8 ounces more. We recommend the Cocoon Silk Mummy as a fantastic option if you want a silk liner but can’t stomach the cost of the Western Mountaineering Tioga.
- Weight: 14.5 oz (0.91 lbs)
- Material: 100% Cotton
- Packed Size: 3 x 6 in
This liner is 100% cotton, perfect for summer trips where you’re looking for comfort more than warmth. This is one of the heavier liners in our review and isn’t as suited for backpacking. We would say the exception is in hot weather where you can use this instead of a bag.
We like that this liner opens on the side and snaps shut so you can easily control how much coverage you’ll have, too. And if the side opening on this liner isn’t on the same side as your bag, just flip it inside out.
✅ Inexpensive option
❌ Heavier option
- Weight: 11 oz (0.69 lbs)
- Material: Brushed Embossed Polyester
- Packed Size: N/A
With a ¾-length side entry zipper, we love getting in and out of this liner. Also, we found it easy to regulate temperature during the night by unzipping the liner for more ventilation.
The brushed polyester material is soft on our skin but is less breathable than organic materials or synthetics with Coolmax technology. This liner will work best with quilts or sleeping bags with a left-side zipper since that is where the liner’s zipper is located.
✅ Insect shield
❌ High-cost synthetic
- Weight: 8.7 oz (0.54 lbs)
- Material: CoolMax Polyester
- Packed Size: 6 x 4.5 in
This sleeping bag liner is a personal favorite of ours if you want a liner with Insect Shield technology. We didn’t find it to be the warmest, but with its excellent comfort we didn’t mind carrying it even with its low warmth-to-weight ratio.
The bug protection makes it a perfect option for cowboy camping. We don’t like that this is the most expensive synthetic option on our list. It’s the bulkiest on our list too.
Key Factors To Consider When Choosing
Consider how much of a priority the thermal properties are to you when buying a liner. Liners with higher temperature ratings will weigh more, and thinner silk liners weigh the least. We recommend nothing over a pound.
The lightest sleeping bag liners:
Sleeping bag liners can be as little as $25 or $80+. Synthetic materials are the least expensive, while lightweight silk liners are the most expensive.
Sleeping bag liners that provide the greatest value:
Affordable sleeping bag liners: Alps Mountaineering Microfiber Mummy
Premium sleeping bag liners (most expensive): Western Mountaineering - Tioga
Comfort is a mix of material, breathability, and temperature rating. Cotton and silk are comfortable on your skin, almost like sleeping at home. They are also very breathable. Synthetics are less breathable and less comfortable. Often they have textures similar to a microfiber towel. The exception is liners with “Coolmax” technology which wicks moisture away from your body. Temperature rating adds to comfort, but if your liner is too warm it can make you sweaty, decreasing its overall comfort.
Most comfortable sleeping bag liners:
Other Things to Consider
UP TO 25 DEGREES
Most companies will provide some sort of temperature rating in the specs. This number is only the additional amount of warmth it can provide. The warmest backpacking liners are rated up to 15-25 degrees. A warm liner will provide extra warmth in the winter and can be used as a stand-alone sleeping bag in warmer months.
TAPERED OR RECTANGULAR
You can get liners that are rectangularly shaped or tapered around the head and feet. The former is more spacious to sleep in, while the latter is lighter and more compact. Some sleeping bag liners also come with an adjustable drawstring around the head to "mummy" it around your face.
BEST FOR COWBOY CAMPING
If you like to cowboy camp (ie. no tent), bugs crawling at night on and around you can be an issue. Some liners come with insect-resistant coated fabrics to deter any unwanted creepy crawlies. If you sleep inside your tent, this feature won't be as necessary.
LOOK FOR COOLMAX LINERS
Sleeping bags can get steamy. You want your liner to help wick any moisture away from your body. Not crucial, but look for liners with the "CoolMax" trademarked feature if you tend to sweat. CoolMax is a cooling technology that moves moisture away from your body and allows it to evaporate from the fabric quickly. Note that merino wool is another fabric that has fantastic moisture-wicking properties.
Ideally, we look for as small as possible for packed size. Silk liners pack down the smallest, while synthetics take up more room. Higher thermal rating liners, i.e. thicker material, will also add to packed size.
Only got $10 for a liner, huh?
Cool. You can always make your own.
You will need some needles and thread and a few hours to spare as well.
Find a fleece blanket or bedsheet at Walmart.
Follow instructions on how to shape and sew your own here.
How to wash a sleeping bag liner?
To wash a sleeping bag liner, the best way is on a gentle cycle with laundry detergent. It's preferable to air dry the liner and not use any fabric softener. If you're using a top-loading machine, SeatoSummit recommends stuffing the liner in a pillowcase to avoid any straps from getting caught in the impeller.
How do you waterproof a sleeping bag liner?
Sleeping bag liners aren't waterproof. If, for some reason, you needed yours to be, you could you wanted to protect, you could simply use waterproofing spray to add a layer of protection after you wash it. After applying the spray, let the fabric dry for at least 48 hours before you pack or use your liner.
What Is the point of a sleeping bag liner?
1. Additional Warmth
Depending on the thickness, a sleeping liner can help insulate a lot of extra precious heat inside your sleeping bag. Example: a sleeping bag rated at 30 degrees, with the addition of a 10 degree liner, could then be rated at 20 degrees.
2. Seasonal Flexibility
A sleeping bag liner is not only great extra warmth in cold weather, but it's also great for warm weather. Instead of packing your heavy and bulky sleeping bag around with you that will be a sweaty oven, you might be able to only pack your liner. They are very lightweight and most can pack down enough to fit inside a Nalgene bottle.
It is a huge pain to wash a sleeping bag. It can be especially painful washing a down sleeping bag. The dry cleaners are super expensive and time consuming. Some cleaners may not know how to treat a down bag and can destroy it's loft and insulation ability. On the contrary, sleeping bag liners are easily washable at home and can save you a trip to the cleaners.
4. Sleeping Bag Protection
On the cleanliness note, by wearing a liner at night, you will inevitably minimize the amount of dirt, oil and filthy hiker grime that reaches your sleeping bag. Protecting a $500 bag with a $50 liner makes a lot of sense.
5. Super Comfortable
Most backpacking clothing is synthetic. Most sleeping bags' material is synthetic. Most hikers long for the feel of bed sheets at the end of a long day. A soft liner to cuddle up inside is the next best thing.
How much warmer are sleeping bag liners?
In general, a sleeping bag liner is 5 to 10 degrees warmer. Some models designed for extremely cold conditions can add up to 20 degrees.
What are the warmest sleeping bag liners?
The warmest sleeping bag liner is the Sea to Summit Thermolite Reactor Compact Plus.
📸 Some photos in this post were taken by Jonathan Davis (@meowhikes)