Guide to buying a sleeping bag

We all know how important it is to get a good night's sleep. Whether you are enjoying the facilities of a recognised campsite or braving the wilds, a good quality, warm sleeping bag will pay dividends.

It is easy to become bamboozled by the numbers, styles and brands on the market, so, as a general rule of thumb, it is worth considering a rectangular bag for warm weather away days on a campsite, rather than for backpacking, when weight becomes an issue. That is when mummy bags come into play.

Rectangular bags normally come with a nylon filling and shell materials, which tends to make them bulky and heavy for the insulation provided. However, they do offer more space, especially around the legs. Mummy bags are more efficient at keeping the body warmer, principally because of their shape, which in itself is more restrictive.

Sleeping bags are filled with either natural goose/duck down, or synthetic fibres. Hardy backpackers, weight-watchers and mountaineers will prefer a quality goose down bag, as the weight-to-warmth ratio is paramount. The bag will almost invariably come with a durable water repellent outer fabric (DWR). Do not be fooled, though. This will not keep the bag waterproof, and a down bag is a devil to dry compared to its synthetic counterpart. It is also going to prove a more expensive option. However, on the plus side, a down bag packs down small, puffs up big, and is wonderfully snug.

So the advice is to try before you buy. Decide on the type of camping you will be doing, set yourself a budget, and try a few bags for shape and comfort.

KEEP WARM, KEEP CLEAN

A liner will add warmth to your sleeping bag while keeping it clean. A multitude of fabrics and designs ensure only your budget will limit choice. Less than a fiver should buy something that will keep the bag clean.

JARGON BUSTER

BAFFLES
Used in down bags only, they feature mesh partitions at quilt lines to prevent cold spots, and prevent down from migrating through the bag.
 
COMFORT RATING
Relates to the lowest temperature at which the bag will keep the average person warm. This should be used only as a guide. Neither should you expect a restful sleep using a bag at the extreme end of its temperature rating.
 
DRAFT COLLAR
Located at the base of the hood, this insulated tube of material is designed to prevent heat loss from around the neck and shoulders. Rectangular shaped summer bags will not normally have one.
 
DWR
Durable Water Repellent coating on the outer fabric to help protect the insulation from moisture ingress.
 
EN 13537 RATINGS
Sleeping bags sold in the EU should now clearly display the standard EN Ratings for temperature. Not the easiest to comprehend, they do provide a standard measure of temperature across different types and brands.
 
FILL (NATURAL/SYNTHETIC)
Fill Power is a measure of the loft of fill such as down, and how well it resists compression. Made from small fibres with chambers to help trap air, synthetic fill is treated with silicone to help enhance loft. When unpacked, the hollow fibres decompress and spring back to gain maximum re-loft.
 
HOOD
Around half of your body's heat can be lost through your head, so a good fitting hood, which can be drawn snugly around the head, can greatly improve the efficiency of a bag.
 
INSULATION
A sleeping bag is designed to trap the non-circulating air between you and the bag. Your body warms the trapped air and, depending on the level of insulation, the warmer you will be. The less empty space there is to heat between yourself and the inside of the bag (think mummy and rectangular shaped), the quicker you will warm up, and stay warm.
 
LOFT
Refers to the thickness or puffiness of a bag.
 
MUMMY
Following the natural shape of the body, a mummy-shaped bag is wider at the top to accommodate the shoulders, tapering towards the feet and into a box-shaped foot section.
 
RECTANGULAR
A sleeping bag cut wide at the shoulders and maintaining the same width down to the feet, giving the user plenty of room to move around.
 
ZIP FLAP OR BAFFLE
An insulated flap normally sewn on to the lining material, that runs parallel to the zipper to block heat loss.

TOP TIPS

Select a bag with the best comfort rating suited to your needs

• Rectangular bags are ideal for low-level family camping and when weight, bulk and transport are not an issue
• If you have not used one before, a mummy bag can feel claustrophobic, so try before you buy
• Zips should have teeth big enough to run smoothly, without catching on the fabric
• If you are right-handed, you will probably prefer a bag with a left-hand opening zip, and vice versa
• If you are planning to zip two bags together, ensure one has a right zip and the other has a left zip
• If camping on a chilly night, close the sleeping bag hood around your head for added insulation, or wear a hat
• Air and dry your bag at every opportunity
• Dry any moisture out of the bag at the earliest opportunity. This is particularly important for down bags
• On returning home, hang the bag for a few days in a dry place to get rid of any lingering smells. This will also allow the bag to breathe
• If going into storage, leave the bag out of its compression sack (some may come with a storage bag) so that the insulation fibres or down are not restricted or break down under prolonged compression

Read more practical camping advice here