Sleeping Bag Materials

Learn which materials go into sleeping bag construction, and their purpose


alan jakeman in snow

Alan is our resident expert on all things wild camping. He loves nothing better than to get out of the house with just his ex-Army sleeping gear and a stove, and head off to the remotest spot he can find near his home on the south coast of the UK.
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When it comes to choosing a great sleeping bag, the most important thing is that it's comfortable, water-resistant, and is correctly rated to keep your body warm for the full duration of your camping trips. 

However, in this article, we'll be deep-diving into sleeping bag materials and discovering how the fabrics contribute to the quality of the above factors.

Sleeping Bag Materials

Types of Materials Used for Sleeping Bags

Various materials are used to make sleeping bags, many of which have different benefits and purposes. For example, some will be better for combatting extreme cold, and others may be better for water resistance.

Shell Fabrics

Shell fabrics consist of a variety of materials that are commonly used in most sleeping bags. The fabric is cheap to make and is therefore used in most everyday sleeping bags. They're the least durable fabric type and are, generally, a low GSM compared to higher-grade sleeping bag materials used by the best sleeping bag manufacturers.

The shell fabric is often the outer layer of insulated sleeping bags. These fabrics are very adaptable for cold-weather activities to help you get a good night's sleep by keeping you warm and comfy at night.

On the other hand, they're breathable, water repellent, and comfortable, so they are very convenient for outdoor use. They don't require seam taping and are designed to be water repellent rather than waterproof.

Shell fabrics are softer, less noisy than hard shell assemblies, and often have enhanced stretching capabilities which is great for fit and comfort.

This category of sleeping bag fabric is designed to suit all figure types and older people's style requirements and may offer comfortable, lightweight protection and adaptability for everyday use.

Shell fabrics have durable water repellent capabilities, which will keep water away from the inner layers and minimize heat loss from sleeping bags to keep them warm.

The gore-tex linings of this fabric add to its water repellent capabilities and make it more breathable to provide ventilation and prevent sweat from building up for enhanced comfort.

The fabric is also windproof to minimize chill and prevent dust from blocking the air pockets to maintain breathability in dusty regions.

These properties and characteristics make synthetic fabric sleeping bags ideal for camping during winter, snow, and dusty periods.


Nylon fabric

Nylon sleeping bags are strong in theory because of their polymer-plastic construct. However, they are not very durable in the grand scheme of things because they're lightweight. Therefore, we recommend nylon sleeping bags for casual family camping trips. 

In addition, nylon is not water-resistant, so you should only use it in drier conditions, so they are perfect for warm summer nights. Finally, Nylon has a great ability to stretch, so it is more durable than other shell fabric materials. 

Nylon fabric is mainly used in sportswear and is inferior to synthetic fabric due to its inability to wick moisture. Thus adult sleeping bags with nylon fabric will not be ideal for camping or sleeping in moisturized or wet areas.

Additionally, nylon fabric has low breathability, so there will be insufficient ventilation in sleeping bags with nylon fabric. This can make the person sleeping inside sweat and feel uncomfortable sleeping in nylon bags.

They are also prone to pulling and bubbling, which can tremendously affect the sleeping bag's quality, making it a poor choice for use in extensive physical activity. Nylon bags have medium heat retention ability, another disadvantage for use in winter and extremely cold weather.

However, where nylon sleeping bags stand out is when it comes to stretchability. They are highly stretchable, which is ideal for fit and comfort.

Nylon fabrics are included in sleeping bags for enhanced elasticity and lightness. So if you're looking for a light and flexible adult sleeping bag, you can consider going with one that has nylon material.


Polyester fabric

In the same vein, Polyester is another shell fabric and is also lightweight. On top of that, they're also both breathable. When you compare both fabrics in a strength contest, Nylon is stronger and has a greater stretchability. 

However, Polyester does resist piling better than Nylon. Piling is when the fabric fibers unravel and create fuzzy balls. Sleeping bags with polyester materials are very fashionable and admired for their durability, easy washability, ability to resist wrinkling, among others.

Polyester fiber adds more cushioning, insulation, comfort, and upholstery padding to sleeping bags. They are highly stain-resistant, which is a cool feature to keep your sleeping bag stain-free and looking nice.

Polyester materials are highly durable and resistant to stretching, abrasions, wrinkling, shrinking, and many chemicals. So your sleeping bag is guaranteed to last longer and withstand abuse while also looking good.

Despite making them very strong and durable, sleeping bags with polyester materials are also lightweight and retain their shape very well. Additionally, polyester fabric makes sleeping bags easy to look after, washable, quick-dry, and ideal for outdoor use.

Polyester fabric sleeping bags are generally hypoallergenic, making them safe to sleep in. However, they can be more expensive than other materials and will need more care with regard to washing and drying.

Consequently, one of the downsides of polyester fabric bags is that they are not breathable. While this can be beneficial in snow and very cold weather, it can make you feel sweaty, making you uncomfortable. 

This is because they have low moisture-wicking capabilities compared to other sleeping bag materials.


Tafetta is the highest quality shell fabric when compared to nylon or polyester. It's crisp, thin, and lightweight. It's smooth, provides a great comfort rating, and is commonly used as dress material. Tafetta does wrinkle quite a bit in comparison to the other materials. 

Tafetta fabric is often considered luxurious and isn't often used because it is prone to damage and is commonly used in high-end women's apparel and wedding attire.

Tafetta materials often make sleeping bags lightweight, soft, beautiful, smooth surface, and iconic to rustling, which is a unique characteristic of this material.

Sleeping bags with Tafetta fabrics are usually crisp and can maintain their shape, which adds to their firmness and stability for a good night's sleep.

This sleeping bag material doesn't pill and can maintain its smooth and beautiful structure overtime to maintain its durability.

Additionally, it is highly breathable, and sleeping bags with Tafetta materials will provide more ventilation to help prevent you from sweating and feeling humid, which is very important in keeping you comfortable.

However, some of the downsides of this material are that it has low moisture capabilities and is less stretchable, affecting comfort and fit.


Blue ripstop nylon fabric

Ripstop nylon polyester is nylon polyester that has been reinforced with heavier threads to prevent tears. It's the perfect solution to mix breathability with durability. 

Ripstop is perfect for slightly more mild conditions and campers who would use it more frequently. In theory, ripstop is the best sleeping bag liner material out of the shell fabrics. 

It tends to be highly breathable because cotton plays a big role in sleeping bags, making them durable and lightweight.

Ripstop helps reduce the wear on sleeping bags fabrics that are in direct contact with the ground or wind to help you get the most out of your sleeping bag.

Additionally, it also allows sleeping bags to be more stretchable and breathable to allow more air to pass through the bag and add comfort.

Liner Fabrics

A sleeping bag lining fabrics helps keep the bag free from dirt and body oils and provides extra warmth to your sleeping bag.

It should be smooth, durable, and breathable enough to provide enough ventilation to prevent sweat when sleeping for an extended period.

There are various types of sleeping bag liners depending on the type of material used:

  • Silk: Very compact, soft, breathable, lightweight, more vulnerable to tears, and mostly found more expensive sleeping bags.
  • Cotton: Durable, strong, absorbed, and suitable for most camping trips.
  • Fleece and microfleece: Soft, moisture-wicking, quick-dry, warmer, but heavier than other sleeping bag materials.
  • Synthetics: More breathable, stretchable, and moisture-wicking, ideal for camping in humid conditions.
  • Insulated: Adds to warmth and greatly extends the range of lightweight bags, and helps sleeping bags dry faster.
  • Polycotton: Ideal for summer or indoor use. Very comfortable against the skin, but less suitable for camping in cold weather conditions and takes a long time to dry.

Things To Consider When Choosing The Best Sleeping Bag Materials

You might find it overwhelming to choose the best materials for your sleeping bag with all this information. To make the decision easier for you, I'm going to walk you through three essential factors to consider when choosing the best material for your bag.

Things to Consider When Choosing the Best Sleeping Bag Materials


It would be best to keep in mind the season and place where you take most of your camping trips.

If you are an all-season camper/backpacker, you won't need a sleeping bag with a down to keep you warm. Instead, you should go for a sleeping bag that has a light fill to keep you warmer on summer nights.

However, if you're camping in the winter and extreme cold weather periods, then the warmest down sleeping back will be able to keep you warm and comfortable at night. 


Are you an all-time camper or a seasoned camper? The more often you go camping, the more you will use your sleeping bag. This will help you decide whether to invest in a sturdier material that can withstand wear and tear and last for a very long time.

If you rarely use your sleeping bag and are taking good care of it when not camping, then there's no need to worry about getting a tough bag; instead, a decent sleeping bag made with nylon or polyester can do the job.


If you're a backpacker and will be carrying your entire bag for a long distance, finding a lightweight backpack will be a good option and will save you a lot of pain. 

Bags with a down fill tend to be lighter and easier to compress than synthetic fill bags, making them easier to carry. A sleeping bag with a down filling will also be easier to fold and stuff inside a backpack.

Investing in a waterproof cover or stuff sack will also be a good idea to ensure that your bag stays dry during rain.

However, the weight won't be significant if you'll be staying at a designated site or are car camping where it's easy to carry your camping gear along with you. In this case, a synthetic fill bag plus a nice sleeping pad will do the job.

Final Thoughts

Along with temperature ratings, sleeping pads, bag materials are among the essential things that make sleeping bags warm, waterproof, lightweight, comfortable, and fit, among others. 

Some of the most commonly used sleeping bag materials include shell fabric, polyester, nylon, Tafetta, Ripstop, and Liner fabrics.

Frequently Asked Questions about sleeping bag materials

Do Down Sleeping Bags Lose Feathers?

This usually depends, but a few feathers can sometimes escape or leak through the seams when the down hasn't fully settled.

Keeping a down bag clean and laundered can help minimize feather loss through the fabric or seams. The down tends to pass through when it collects body oils easily. The small quilts and slick matted down feathers are likely to pass through any tiny opening along with the stitching.

You can simply reach behind and pull the feather back if it starts partially coming out, or moisten and massage the fabric a little if it leaves a small hole. However, this is not something to worry about, and it's typical for sleeping bags to lose feathers.

What is a GSM Sleeping Bag?

You might have seen the word "GSM" on sleeping bags and have no idea what it means.

GSM means gram per square meter, and it measures the density of the filling or insulation of sleeping bags.

A high GSM number on a sleeping bag means that the bag will be able to retain heat and keep you warmer in cold weather conditions than bags with low GSM ratings. The higher the GSM rating, the denser the filling of the bag.

Many factors contribute to the warmth of sleeping bags, and GSM rating is one of them. Sleeping bags with low insulation usually use the term "down-fill power" ratings rather than GSM, with an average between 400 to 500.

A higher GSM rating doesn't always mean better warmth because the performance of insulation material also depends on quality. 

How Many GSM Are In A Sleeping Bag?

GSM ratings wildly range from around 67 to 950. For sleeping bags, you're going to see a GSM rating in a wide range due to need. 

The GSM rating for sleeping bags can be low, around 100GSM, or as high as 900GSM, depending on the bag's design. Sleeping bags made for snow or cold weather will likely have higher GSM ratings.

Below is a breakdown of the common GSM ratings for sleeping bags:

  • 100GSM & Under = 32 Degrees & above
  • 200GSM to 300GSM = 20 - 32 Degrees & above
  • 400GSM & above = 20 Degrees & below

Is A 300GSM Sleeping Bag Warm?

A 300GSM sleeping bag is expected to have temperatures around 32 degrees which can be considered warm.

Are Synthetic Sleeping Bags Good?

Synthetic sleeping bags are good, but you should remember that not all sleeping bags are created equal, just like any other camping gear.

Synthetic sleeping bags can be good in wet and rainy situations and will insulate and keep you warm. During wet weather and water activities, a synthetic sleeping bag will insulate you, keep you warm and perform better than their down counterparts.

Synthetic fill is typically made of polyester, which is quick dry and can provide you with insulation which is something down struggles to do. They are also durable, hypoallergenic, and less expensive than down insulation.

Why Do Sleeping Bags Have 2 Zippers?

A woman inside a sleeping bag

Sleeping bags have two zippers to provide you with better comfort around your shoulders, better internal ventilation to manage the temperature inside, and for easy on and off experience.

The dual zipper feature makes it more comfortable by allowing you to close the bag securely and tightly. This is important in sealing your body thoroughly within the bag to prevent air from getting into the bag.

By opening the bottom zipper, you will substantially increase the amount of airflow to the bag for proper ventilation, regulate the temperature inside, and get a little more comfortable.

The two horizontal zippers of sleeping bags will give better access and flexibility for both hands to adjust the bag accordingly.

Which Is Better Silk Or Cotton Sleeping Bag Liner?

Choosing the best liner for your bag depends on various conditions; Silk liner is lighter, more luxurious, and can be a good choice for backpacking. It can extend the warmth of your bag and make it dry quickly, but the downside of this liner is that it can be expensive.

On the other hand, cotton is more affordable and is one of the cheapest options available. Though it feels good on the skin, it has many downsides when compared to silk liners. 

Cotton doesn't add warmth to the bag, can take more time to dry, and can sometimes be somewhat irritating.

So looking at these facts, we can say that silk liner is better than cotton, though each has its advantages and disadvantages.

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