5 Best Sleeping Bag Liners

Sleeping bag liners get used for everything from standalone summer blankets to wintertime insulation boosters. Personally, I use a thin nylon liner for many of my down quilts to help protect them from dirt, skin oil, and wear. Whatever your needs or goal, a sleeping bag liner is usually an inexpensive addition to your sleep system meant to supplement your existing set-up.

Be warned, however, that most sleeping bag liners won’t add as much warmth to your sleeping system as many would prefer. Time and again I have talked to backpackers disappointed by the advertised warmth rating of bag liners. What this means for you is that it’s important to understand the uses and limitations of your new sleeping bag liner.

With that in mind, we’ve listed below the five best sleeping bag liners available today and briefly reviewed each. We’ve included options that cover a range of prices and styles to help you find the right bag liner for your needs.

Top Pick: Sea to Summit Reactor Extreme Thermolite Liner

Sea to Summit has been producing backpacking and hiking equipment for years, and I personally rely on several of their products.

So why did we choose their Reactor Extreme as our Top Pick?

It comes down to warmth. Because sleeping bag liners have a tendency to provide less insulation than desired, I find it easier to err on the side of too warm as you can always take some layers off. Among popular bag liners, the Sea to Summit series offers the widest breadth of warmth options, and the Reactor Extreme is their warmest offering.

This liner weighs just 14oz and can add up to 25 degrees of warmth to your sleep system. It’s a good choice for a light summer blanket or an addition to extend the usability of your 3-season bag. It’s worth noting that, as a standalone blanket, this bag liner won’t provide much warmth. Expect it to be comfortable to no lower than 60 degrees by itself.

Best Value: Coleman Stratus Fleece Sleeping Bag Liner

One of the challenges of putting together an outdoor sleep system is accommodating multiple sleepers. If you want to go hiking or camping with your partner and share a comfortable bed, good luck! It’s surprisingly difficult to find good, affordable solutions.

However, the Coleman Stratus Sleeping Bag Liner is an exception. It comes in at a very affordable price. It’s also one of the best fleece liners available.

The Stratus adds up to 12 degrees F of extra heat to most sleeping bags. That’s right — no need to buy another sleeping bag just for colder weather. You can turn your 3-season bag into a 4-season bag with this liner alone.

Coleman even claims you can sleep in the Stratus on its own in temperatures as low as 50 degrees F. That sounds a bit crazy to me, that’s the temperature rating of some sleeping bags, but it gives you an idea of the warmth of this liner.

Budget Pick: California Basics Sleeping Bag Liner

This is the best option for those on a shoestring budget. Beating all of the other options we’ve reviewed with a low price and simple polyester bag liner construction, you’ll be hard pressed to find a more value-conscious option.

Keep in mind that while there are lighter and warmer options available, the main goal of this pick is to keep the price low for you!

There’s really no additional warmth to be gained from this bag liner. However, if you’re like me and want to protect your expensive sleeping bag or backpacking quilt, you’re probably looking for something lightweight and inexpensive. This liner comes in at 14oz, so it’s not the lightest, but it certainly is reasonable for those looking to gain the benefits of a bag liner without taking a hit to their pocketbook.

Runner-up: ALPS Mountaineering MicroFiber Mummy Sleeping Bag Liner

ALPS Mountaineering is a well-known name in hiking and backpacking gear. Among major manufacturers producing bag liners right now, the ALPS products are reliable and affordable.

Make no mistake, however, this bag liner is meant first as a protective layer and second as a marginal warmth addition. It weighs in at about 12oz so it’s not the lightest solution available but it does have a few advantages.

What I like about this bag liner is that it’s shaped to fit most mummy bags which are by far the most popular sleeping system on the trail. Many competitors use rectangular bag liners which won’t fit the popular mummy bag style nearly as well. If your primary need is sleeping bag protection from dirt and grime, this is a great solution from a good manufacturer at a price that can’t be argued with.

Upgrade Pick: Cocoon Silk MummyLiner

Why the Upgrade Pick? Because silk has been a luxurious fabric for centuries and, to this day, many still swear by its properties.

Warm in the winter and cool in the summer, silk is a great next-to-skin fabric and is a huge improvement over the feel of nylon or polyester used in most bags and bag liners. Silk dries quickly and the ripstop weave used in this silk bag liner lends durability to the material for a long usable life.

Oh, and did I mention that the entire bag liner weighs just 5oz? If you’re looking for a great lightweight sleeping bag liner, this one’s for you.

This is definitely not a bag liner for those looking for additional warmth, though. It will, however, provide a very comfortable sleep while protecting your main sleeping bag or backpacking quilt against body oils and dirt accumulation. Body oils and dirt can eventually negatively impact the insulative qualities of down bags. I personally use a thin nylon bag liner to protect my quilt for these reasons and the Silk MummyLiner is a great option that’ll do just that — of course, though, for a higher price.

How to Choose the Best Sleeping Bag Liner for Your Needs

Weight

While we’d always like to carry the lightweight option, we have to accept that the warmer the bag liner, the more it usually weighs. If your goal is to use the bag liner to keep dirt and grime off of your sleeping bag, then we recommend making weight most important criterion. If, however, added warmth is your primary goal, you’ll need to accept a heavier overall weight.

Temperature Rating

Determining your overall temperature rating can be a bit more of an art than a science. Many backpackers will choose their sleep system based on the record low temperature for the region and time of year they expect to be traveling. I recommend this system.

Be sure to test your sleep system in a safe environment such as the backyard or a modern campground before relying on it in the backcountry. In case you’ve made a mistake in choosing your sleeping equipment, it’s best to discover this in relative safety!

Material

By far the most common material I see bag liners made of is polyester. It’s a common insulation material and tons of outdoor gear is made from polyester thanks to its wicking qualities and relatively inexpensive cost. Nylon is also a possible bag liner material though you’re unlikely to find this unless you make your bag liner yourself (easy to do) or have it custom-made as I had done with mine.

I highly recommend avoiding thermal emergency blankets such as the aluminized reflective survival blankets. These are made for very specific conditions and function best when used to reflect infrared heat back at your body. They’re not really meant to insulate directly and you’ll be very uncomfortable wrapped in a plastic sheet all night.