Sleeping Bag Liners
Hiking practice
Sleeping bag liners; what are they used for and why should you consider using them if you are into overnight camping? As the name suggests, their main use is as a liner for sleeping bags but they are so much more and are a very versatile piece of gear that many hikers don’t even consider, but should they?
What are they?
Sleeping bag liners are essentially pieces of material (of various kinds) that are designed to line a sleeping bag. My first interaction with them occurred many, many years ago when I would go camping with keen family friends. In those days, my friend’s mother who was handy with a sewing machine would take old cotton sheets, fold them in half, and sew them along the bottom and side to make a ‘bag’ that would then be used as a liner for our sleeping bags. The main aim was to protect the sleeping bag from mud and dirt. If you’ve walked trails like Tasmania’s South Coast Track you know it can become very muddy indeed! Even if we stay relatively clean, our bodies naturally produce oils and sweat and on longer hikes we don’t stay as clean as we would do at home.
Between what we produce naturally from our bodies and what dirt we pick up from our trail, it can potentially impact the performance and durability of a sleeping bag because the grime from our bodies soaks into the bag itself – so this is where sleeping bag liners come in handy.
What can they be used for?
So, are sleeping bag liners just a protective shell to keep our sleeping bags clean or do they have other functions? Here’s what sleeping bag liners can also do for you.
A sleeping bag liner
- As already mentioned, at there most basic they line your sleeping bag and help to keep it clean
- If you are needing to hire a sleeping bag, a liner will also add a level of protection and comfort
Very muddy section on the South Coast Track
Tim at the Cockle Creek Trailhead (end of track) on the Tasmanian South Coast Track. You just can’t help but get dirty on this trail
As a thermal layer
- If you only ever camp in one type of climate at the same time of the year then you can usually get away with just one sleeping bag. But start camping in different climates at different times of the year and you will usually find that you will need a second sleeping bag (one cold climate and one warm climate) to suit all your needs
- A thermal sleeping bag liner creates a layering system for your sleeping bag that, in addition to it keeping your sleeping bag clean, can boost up the warmth. This means you can extend the temperature range of your sleeping bag
Sea to Summit Reactor Supreme Compact Sleeping Bag Liner boosts the warmth of your sleeping bag
As a standalone sleeping bag
- I’ve had some nights where the temperature hasn’t dropped below 20º Celcius and when you have a night like this, the last thing you want is a down/synthetic sleeping bag that keeps you warm down to -9º Celcius even if you can unzip it fully open
- If you can be sure you are going to have hot nights on your overnight trips, then why carry a heavy grade sleeping bag? But for many hikers the use of a sleeping bag liner never crosses their mind
- One thing to note here is you should always come prepared for the coldest conditions you will expect. If it gets hot and all you have is a heavy grade sleeping bag, you can always sleep on top of your sleeping bag if worst comes to worst
Sea to Summit Reactor Extreme versatility. If you feel so inclined you can walk around camp in this bag if its cold by undoing the bottom of the liner and you can use it as a stand alone sleeping bag if its warm
As a bottom sheet
- Another option for sleeping bag liners is to use it as a bottom sheet
- This tends to be Gill’s main use for her bag liner as she finds that it minimises the noise from and movement of her sleeping pad. In her case, she puts the sleeping pad inside the liner and then sleeps on top, hence creating a ‘bottom sheet’ over her sleeping bag
- Interestingly enough, Therm-a-rest now makes a dedicated bottom sheet (the Synergy Lite Sheet) added to its sleeping pad range that comes in various sizes
What options do you have?
In deciding which sleeping bag liner is for you, you need to work out why you might need one to identify your main options. You could then decide to make one or buy one.
Make your own
- If all you want is to keep your sleeping bag clean then you can sacrifice one of your older single sheets or for that matter, you can buy a new one for around AUD $20 RRP
- A standard Australian single sheet is 180 x 254 cm but you won’t need to use the whole sheet trimming it down to something smaller that suits your preference
- Having basic sewing skills, or at least knowing someone who does, is a big help here!
Buy a commercial one
- There are plenty of options on the market these days but by far the main ones you will see are from Australian company Sea to Summit
- Commercial sleeping bag liners vary in cost, weight and thermal properties so you need to identify the features you are after
Sea to Summit Silk and Cotton Travel Sleeping Bag Liner. This liner combines silk and cotton, is lightweight, and designed purely for keeping your sleeping bag clean
Sea to Summit Thermolite Reactor Extreme Liner – a heavier liner at 342 grams but with that comes much greater insulative properties including a hood and the ability to open up the foot box of the liner. So, if you want to beef up your warmth in the colder weather then this is a great option
The Final Word
You may have never considered a sleeping bag liner as an option in the past or even dismissed this as an unnecessary luxury. However, I have used a liner in one form or another since my late teenage years so it’s been a while! We both own a lightweight liner for the majority of our overnight adventures as well as a thermal liner which we use as a standalone sleeping bag in warmer conditions or as a thermal boost during cold weather.
Think of a sleeping bag liner as a versatile piece of overnight equipment that will not only improve your camping enjoyment but will also prolong the effective life of your sleeping bag which is typically one of the most expensive pieces of gear that hikers will own.