Frequently asked questions about sleeping bags and mats

In general, down has the advantage of being one of nature's most effective insulators while still being a lightweight material. Therefore, down sleeping bags often have the advantage of reaching the same performance as a fiber sleeping bag and still be lower in weight and take up less space, which gives a good heat-to-weight ratio. However, down generally has the disadvantage when it comes to wet conditions.

The filling in a Nordisk fiber sleeping bag is a synthetic product made from "fiber hairs" that trap air. Finer fibers provide improved insulation performance. It has a very high level of insulation and is highly durable, additionally, it dries quickly, doesn't absorb water and it only requires a minimum of maintenance.

Fiber filling ensures a sleeping bag with a pleasant and soft feel combined with high elasticity and very good heat insulation.

Compared to down filling, a synthetic sleeping bag requires less care in cleaning and storage, and it also performs better when wet. Furthermore, since synthetic filling is less costly than down, a fiber bag offers relatively good value for less money.

Down bags are very soft with a unique weight-temperature ratio. Choosing down you get small pack size and lower weight, but the trade-off is that it is more vulnerable to moisture and getting wet. Down has an excellent warmth-to-weight ratio and breathes well. Nordisk only use high quality European down some of which have a special treatment to make them dry faster called Crystal Down® Dry.

Read more about our Crystal Down® on Down Specialist.

It is very important that a sleeping bag is neither too big nor too small. Both scenarios will compromise the heat retention. Always make sure you are somewhat below the “body length” count that is stated under “Measurements” for each sleeping bag on our website.

Medium: Up to 175 cm.

Large: Up to 190 cm

X-large: Up to 205 cm.

Additionally, be aware of other measurements such as width at the shoulders and hips.
If you wish to store clothes in your bag, maybe size up to make sure there is space.

We are very proud to declare that all our down sleeping bags are handcrafted and produced in our own factory in Görlitz, Germany. We’ve been doing it since 1983 and have a team of very skilled seamstresses who handle the daily production. Therefore, we can also always repair or refill your sleeping bag so as if it was new again.

The fabric used for sleeping bags is divided into two main categories: The shell and the lining.

The shell fabric typically has the job of ensuring that no fibers or down leave their intended place. The shell fabric can be thicker and more rugged to protect the sleeping bag when in use.

The lining is the part that is in contact with your body and is therefore often thinner, lighter, and softer to offer maximum comfort. For Nordisk sleeping bags, we use a variation of soft nylon, brushed polyester or cotton depending on the type of sleeping bag. Generally, the lining fabric is chosen to support perspiration management and softness inside the bag.

Yes, with one exception. All Nordisk sleeping bags are free of intentionally added PFAS, except Arctic, which has waterproof features and needs a reliable coating.

Sleeping bags are rated with three temperatures. The definitions below follow the European standard for sleeping bags (ISO 23537). The temperatures are a guideline, as everyone has different needs for warmth.

Comfort
The lowest temperature at which an average woman can sleep comfortably in a relaxed position.

Limit
The lowest temperature at which an average man can sleep for 8 hours in a curled-up position without waking from cold.

Extreme
The lowest temperature at which an average woman can stay in the sleeping bag for 6 hours without risk of hypothermia. It is not a temperature you can sleep comfortably at.

The temperatures assume the sleeping bag is the right size and shape for you. A liner or wool nightwear can help raise the temperature inside the bag.

A few factors can be the cause of you freezing in your sleeping bag, even though it’s made for the required temperature. Sleeping bags insulate by trapping air in the fibers/down filling, this air is warmed up by your own body heat. Having too big a sleeping bag will increase the amount of air having to be warmed up, which can make it seem colder. Conversely, too small a sleeping bag will also give a colder experience (compressing the filling).

A few things can be done to maximize the performance:

1. Make sure to put out your sleeping bag at least 30 mins before you plan on using it. This way the fibers/down aren’t compressed and have a chance to puff up, making them able to trap more air. Do not move too much in the bag.
2. Do a few exercises to get your blood flowing before going inside the sleeping bag. (Not so much that you start sweating, as this will have a negative effect).
3. Warm up the sleeping bag before going to bed by putting it around you as a blanket.

Curve, Mummy, Egg, and Brick is simply a description of the shape of the sleeping bag. The different models are designed to accommodate different shapes and sizes for different performance needs.

Curve

A sleeping bag with a snug fit slimming in at the waist and feet but broader at the shoulders and hips.

Mummy

A sleeping bag with a somewhat tight fit. Broad at the shoulders but slimming in all the way to the feet. This may vary depending on the individual sleeping bag.

Egg

The Egg (comfort) fit has a lot of the advantages of the curve and mummy but gives a bit of extra space in comparison. It's normally thicker/more insulated to achieve the same temperature.

Brick

A sleeping bag with a rectangular fit, a lot of space and can be zipped all the way up to be used as a duvet or blanket. Offers great comfort but a poorer performance overall.

The curve shape by Nordisk offers a good balance between insulation and space. Most people sleep in a "running" position where the body makes an s-shape. The curve shape allows more comfort and space for this position. Gives more room for the shoulder/chest and knee/lower leg areas.

The mummy shaped sleeping bag has a strong insulation-to-weight ratio as it seals your body tightly, making it thermally efficient. The mummy shape offers a lot of warmth for its fill, but it also has a limited internal space.

For those who want some extra space, but still want a technical bag designed to withstand tough conditions, the egg-shaped sleeping bag is the right choice. Not as tight fitting as a mummy or curve shaped bag, but much better insulating than a rectangular sleeping bag.

The rectangular sleeping bag is spacious and comfy as it provides extra space for those who really like to move inside the bag. All our rectangular models have an all-around zipper making it possible to use the sleeping bag as a blanket as well.

In some of our more extreme sleeping bags we use the down filling Crystal Down® Dry Down. This down is treated with a PFAS-free durable water-repellent coating that makes the individual down clusters moisture repellent as well as faster drying. All this without compromising the insulation power of the down.

It is impossible to make sure that every sleeping bag is 100% down without any feathers being present. In any Nordisk down sleeping bag there will be a minimum of a 90/10 mix, which means that 90% are down with 10% being feathers. In some of our more exclusive models we promise at least 95% down and 5% feathers. Feathers are not harmful and are so fine they also help insulation and keep structure.

Cuin is a measure of the insulation power of down and is short for “cubic inches”. The number tells you how many cubic inches one ounce (about 28 g) of down fills, measured with a standardised method. For example, the Walløe sleeping bags use 800+ cuin down. The higher the cuin, the finer the down and the more air it traps. Another term for this is fill power or loft.

We develop equipment for explorers, exploring the most difficult places to reach in the world and therefore, all our down bags are filled with Crystal Down®, a selection of voluminous European down. A single Crystal Down® can have a diameter of up to 4 cm and white fluffy "arms" to entrap air and support insulation. We ensure that the down we use lives up to standard European down ethics.

Nordisk Crystal Down® is European down. It primarily comes from a species called Koluda, which is a large type of goose, and this gives high quality and large down clusters. Our down is RDS-certified.

Yes. Always try to air the sleeping bag first, as this is preferred. Sleeping bags can be washed once in a while, however you have to use caution when wanting to clean your down sleeping bag. Use a down wash and if your machine has it, a down washing program on a low (30°C) temperature. Make sure the washing machine is detergent free. Tumble the sleeping bag dry on a low-temp. dry cycle and throw three tennis balls into the tumbler to re-fluff the down.
It can take 4-5 hours. If it is not dry, repeat. Hang it up afterwards.

Yes. Only wash your sleeping bag if it’s dirty or smells. Use a very mild machine wash at 30°C and afterwards tumble dry at a low temperature. Follow the washing instructions on the tag that’s found inside the pocket.

You should neither wash your sleeping bag too often nor never. After extended use of a down sleeping bag the down fibers will slowly absorb sweat and oils secreted from the body. Another sign that your sleeping bag is in need of a cleaning is if the down starts to get flat. A proper wash and dry will often restore it to its former puffy glory.

It is always advised to store your sleeping bag out of the compression bag. The best-case scenario is to hang it on a coat hanger in a closet or laid out. Alternatively use the storing sack that accompanies the sleeping bag, do not keep it stored fully compressed. This goes especially for down sleeping bags, as compressing it over a long period of time can harm the down. Also make sure to store it completely dry and avoid humid environments.

During the trip make sure to:

1. Get the sleeping bag out of the stuff sack and hang, lay, or toss it somewhere dry (occasionally).
2. Avoid laying on sharp rocks, edges or the like.
3. Keep dirty clothes and food out of your sleeping bag

Care after use:

1. Shake the sleeping bag before packing it up.
2. If possible, dry the sleeping bag (i.e., in the sun) before storing to reduce dampness and mold.

Care before storing:

1. Clean the outer fabric. Often wiping with a wet wipe or moist cloth is enough on nylons.
2. If it's dirty you might consider washing your bag, but don’t do it excessively.
3. Do not bleach, wring, or iron your sleeping bag!
4. Never store moist, neither the sleeping bag itself nor the room it’s stored in.
5. Douse a cotton ball with lavender oil and drop it inside to avoid last season’s odor during the off-season storage.

It is normal for all down products to sometimes leak some feathers. It is impossible to avoid but do not worry. What is getting through your down product is usually just some of the feathers, and not the insulating down. When a feather eventually sticks through, do not pull it out as this will sometimes enlarge the hole in the fabric. Instead, gently pull it back by holding the fabric and massage the fabric afterwards, and most often the leak will be stopped. Sometimes you need to pull out the feather, then make sure to hold the down back and only pull out the feather.

In case your Nordisk down sleeping bag gets a rip and loses the insulation, you can always have it repaired and refilled at our Care & Repair center in Görlitz, Germany. We will, for a cost, refill and repair the sleeping bag so it’s as good as new.

R-value measures how well a sleeping mat insulates you from the cold ground. The higher the R-value, the better the insulation. Most mat brands measure R-value with the same test method (ASTM F3340-18), so values from different brands can be compared.

As a guideline:

• Under 2: summer and warm nights (around 10 °C)
• 2 to 3.9: three-season use (down to around 0 °C)
• 4 to 5.4: winter and nights below freezing (down to around -7 °C)
• 5.5 and above: extreme cold (-18 °C and below)

R-values add up when you stack mats. A foam mat under an inflatable mat gives you the combined R-value of both.

Sleeping bag temperature ratings are tested on a well-insulated mat, so a mat with a low R-value will make your sleeping bag feel colder than its rating. Thickness alone does not decide the R-value, so always check the specifications.

When buying a sleeping mat, the shape influences both performance and comfort. Choosing the right shape, size, weight and thickness therefore determines how warm and how comfortable you are laying, when using the mat. Nordisk has four basic shapes:

Rectangular

The classic shape usually used for larger mats. It offers great comfort as it normally is both longer and wider, and often also thicker.

Mummy

The mummy shaped mat shaves off a little weight, but still ensures relatively high comfort. It has a much better pack size than a rectangular mat and a lower weight.

Body contoured

This shape shaves off all unnecessary material and thereby minimizes weight and pack size. It only insulates where it matters.

Torso

This mat protects only the most critical parts of the body. It is extremely packable and is mainly for use where weight is key. Use another solution (or none) for your legs.

The type of mat you use for your trekking tent is dependent on the circumstances of your trek and what kind of tent you bring along. For our smaller trekking tents, such as the Lofoten and Svalbard, you do not have a lot of space in the sleeping cabin. This means that you won’t always have enough space for a rectangular sleeping mat that is too thick/high. Be especially aware of the thickness, as too thick of a sleeping mat can mean that your feet will touch the “ceiling” and get wet due to condensation or rain.
When choosing a mat, make sure to look at both the dimensions of the tent as well as the mat. The sleeping mat should not rub up against the sides of the tent, as this changes the shape of the tent, which helps water get in.