The Ultimate Guide to Sleeping Bag Liners

Sleeping bag liner

Our mission is to get people outdoors, not sell gear. That's why our guide starts with the core function that needs to be addressed, then helps you evaluate your options holistically, since sometimes you may not need any gear & can use what you have at home. We want you to think critically about what you need, which is personal to you with no right answer (some people go venture outside naked without any gear, survive & have a great time).

Core function: There's not a core function for sleeping bag liners. You can think of them as sheets, a very multi-purpose piece of bedding! Commonly, these are used: 1) for warmth - either in addition to the sleeping bag or as a standalone blanket, or 2) for hygiene (a barrier between you and the sleeping bag, like how in the hotel the sheet is a barrier between you and the duvet).

Click here for a high level overview of how insulation works, which can be helpful to understand the terminology & concepts used throughout this page.

Is either the core function or the outdoor-specific gear made for it an essential?

No .

For rationale, read our 'what you really need' protip

What to use & how to choose

Key factors

Cool zippers, new waterproofing, etc... sometimes it's easy to get lost in all the hype (over-spending happens on features). Our guide focuses on the fundamental factors you should always keep in mind (thus, this short list is similar across all items). Then only at the end do we have some questions to get you thinking about other minor features.

We highly recommend reviewing Type or Style first, where we review what you can use to address the Core function--a regular item you have at home may work! The other factors are secondary & depend strongly on the Type or Style you've picked.

While we encourage you to use regular items wherever possible, as an outdoor gear shop, we only carry outdoor-specific products

Type or Style

We've organized the most commonly used items people use to address the Core function below, with example images, characteristics, features, etc.

With sleeping bag liners, like with sleeping bags, there are 2 primary dimensions that you should consider in terms of type or style.

Name Sheet Sleeping bag liner*
Single sheet, thinner than a blanket Think of a sheet folded in half & stitched together, may also have a hood
Example images Sheet Sleeper bag liner
Effect on secondary factors Price $10-50 $10-60

Warmth

Given shape-only

No comparable temperature rating

Not enclosed, so doesn't keep out drafts & may create excessive dead air

Adds up to 8F (4.4C)

Enclosed & may be form-fit to minimize drafts & excessive dead air

Capacity Twin to king size Individual sized
Weight Not optimized for weight Up to 16oz (454g)

Why we do/don't carry it

= we rent

= we sell

Not specific enough for outdoor use

Standard for most outdoor uses

*Sleeping bag liners also come in rectangular or mummy shape. Since this shape impacts secondary factors similarly as we've already discussed for sleeping bags, and the shape is less of a big deal since the liner is more of an accessory item, we have not separated liners into shapes here.

With any of the form factors above, a difference of material is also significantly important. That said the data on the materials below is only for sleeping bag liners, not sheets (since they are not optimized for the technical factors we'll consider below, e.g., warmth or weight & size).

Sleeping bag liner material Silk Synthetic (e.g., microfiber) Cotton
Effect on secondary factors Price $40-60 $20-40 $10-30
Warmth*

Up to 8F

(4.4C)

Up to 6F

(3.3C)

Up to 4F

(2.2C)

Weight & Size

Up to 6oz

(170g)

Up to 10oz

(283g)

Up to 16oz

(454g)

Why we do/don't carry it

= we rent

= we sell

Much more expensive relative to the improvements in weight savings or warmth

Versatile for most outdoor uses, therefore more worth the money

For rent for sleepers who need extra capacity; extremely limited availability, please call to reserve

We only offer liners for rent since most people would just buy a sleeping bag (whereas with rentals, even though bags are sanitized between uses, some people want a hygiene barrier)

*Warmth added when paired with a sleeping bag. Whether the max is attained really depends on individuals, your body heat generation, other layers, etc.


The first 3 factors: Price, Warmth, and Weight & Size are more related to Material differences (see above) than to there being multiple models of sheets or sleeping bag liners with different thicknesses.

Capacity (size)

Like a sleeping bag, there are larger liners for larger people. Since liners are already so small & lightweight, we won't do an in-depth analysis here, but the same concepts apply as from sleeping bags: the larger the liner, the more expensive & heavy. And with larger liners, there's a trade-off between roominess & insulation.


Minor features that may be important

Here, we give you a list of questions to start thinking about minor features. We hope our approach of savings these features for last gets you to more critically think about what you need & not get caught up in the hype of what's cool and over-spend your budget.

  • Is it completely stitched shut or does it use buttons or velcro so that you can undo it (similar to unzipping a sleeping bag)?
  • Is there a way to cinch it tight around you?
  • Does it have a hood?

What we carry

General Notes

  • We choose what we carry based on extensive research on what's the best value to our customers (e.g., price given performance & durability features) across all the top brands. We specifically do not carry every brand & model; for details on why we do/don't carry certain items in the How To Choose section
  • Buy prices are MSRP with tax, i.e., what you see is what you pay. Prices may differ in-store due to change in models or discounts, but this is rare. If we don't sell what we rent, we list MSRP value with tax
  • Rent prices are the starting prices; enter trip dates on our Catalog to get exact prices (based on total trip length, not per day!). We also don't charge sales tax, an automatic savings of almost 10%!
Material Synthetic Cotton
Mummy-shaped Rectangular-shaped; fully opens, best if more space is needed
Model Cocoon Microfiber liner Cocoon Cotton liner
Cocoon Microfiber liner Cocoon Cotton liner

Buy

MSRP with tax

$27

value

$33

value

Rent $5+
Weight

9oz

255g

15oz

425g

Carry size & notes A regular burrito A super burrito

When you rent online, we will pick a model for you. You can change the model if you pick-up in-store, subject to availability. On the Options page of our online order process, you can also select options or write-in any preferences. This section describes the majority of our models & options, but sometimes we carry others. We will only pick something else if it doesn't conflict with your choices indicated on the Options page; moreover, if there's a major functional difference (e.g., capacity), we will attempt to contact you first

Usage tips

It's easiest to get into your liner first, and then get into your bag!

Maintenance tips

Cleaning

This can be washed in a regular washing machine, like doing sheets

Repairing

Sew up rips, tears, or holes, or apply a patch; generally any tailor should be able to do this

Storing

Store when clean & dry. Since this is basically just a sheet, it's less imperative to store it loosely, as it is with other gear

We have a general protip on how to store & maintain gear that we highly recommend reviewing as well. If you send us video or a good photo series, we may be able to help you evaluate your repair needs.

The exact numbers (e.g., weights, dimensions, prices, etc.) used were updated as of September 2019 . That said, there usually isn't dramatic change; we update & review the market roughly biennially.


Thoughts, ideas, questions? Let us know in the comments below! We're Last Minute Gear, the only outdoor gear shop where you can buy, rent, or borrow gear!