How to find the best sleeping bag
A sleeping bag is one of the most important pieces of outdoor gear to get right at purchase. Sleeping bags provide shelter, warmth and comfort, so buying the right one for the conditions you are expecting to experience is paramount.
Sleeping bag choice will be heavily influenced by how your body works; whichever one does the best job of keeping you warm and comfortable will be the bag you need.
A sleeping bag’s temperature and comfort rating plays a big role in your choice and, again, will be dependent on what conditions you are camping in. For most Australian conditions (including the High Country and the central deserts), a bag rated around 0 degrees Celsius (or three-season) is the best all-round option. However, because everyone is different – some people are ‘cold’ sleepers and others are happy in sub-zero temps with only a very light bag – you will need to test as many bags as you can to achieve the best ‘fit’.
Whether to opt for a down-fill bag (usually goose-down) or a synthetic-fill bag is the main decision you will need to make. Either option has advantages and disadvantages (see Materials).
A bag’s fill weight, as opposed to its overall weight, and its ‘loft’ rating are two very important figures. The loft rating, measured in cubic inches, records the volume of the bag that is filled by expanded down. Basically, the higher the loft-figure (and the ‘puffier’ the bag when laid out), the higher quality down and better heat retention. Fill weight is important, too, as it tells you how much of the bag’s overall weight is actually fill (which creates the bag’s warming attributes). Again, the higher the better as more fill generally equals more warmth, as long as the loft figure is reasonable – between 600 and 800 is ideal for all-rounder sleeping bags.
Sleeping bag shape (or style) plays a major role in final choice. For the best warmth-retention capabilities, a mummy-cut bag is the best option. This is due to its compact shape ensuring that there is minimal ‘spare air’ for your body to warm up. However, mummy bags can be constricting for some and make for an uncomfortable night’s sleep. Rectangular bags are the exact opposite: there’s loads of room inside, with the result being that your body has to work twice as hard to warm up all that vacant space. Semi-rectangular, or relaxed-mummy bags are the ideal compromise for those who don’t want to be overly constricted or spend the whole night trying to stay warm in a voluminous bag.
How heavy a bag is – and how compact it packs – may or may not be important, but it is reliant on the materials used – with the biggest material influence the actual fill type that is used in the bag. The majority of sleeping bags use synthetic fibre (nylon or a variation of) for the outer shell, but buyers have two choices for the fill material: down or synthetic.
For decades, down-fill bags have been the preferred option due to that fibre’s better warmth for weight performance – plus, it also means the sleeping bag will pack down more compact as down is more compressible. For vehicle-based camping, this may or may not be a huge issue, depending on whether you’re traveling in a big LandCruiser, or a smaller, more compact Subaru Forester SUV.
However, Synthetic fill technology has advanced incredibly in the past decade to the point now where a synthetic-fill bag is a viable option for even the fussiest of sleepers; the latest tech synthetic fill compresses like down, while offering close to the warming capability, albeit still with a weight disadvantage. Again, a 500-gram difference in sleeping bag weights may not be an issue for vehicle-based campers, and you’ll pay a reasonable amount less when forking out for a synthetic-fill bag.
Pros and cons
Down is still the optimal choice for most ‘serious’ outdoor sleepers. Its warmth-to-weight ratio, its compressibility, it has a longer ‘life’ compared to synthetic, and it is more resistant to odour retention. It does have its negatives, though: if you get your down-fill sleeping bag wet, it will just be wet and cold – it will not offer any warmth at all. Aussie company Sea To Summit now offers a water-resistant down fill, that does alleviate this somewhat, but it is pricey. Plus, it is, as mentioned earlier, very expensive.
Synthetic-fill bags’ biggest appeal is they are cheaper (sometimes significantly so), can offer the same warming capability (albeit with a weight penalty), and will retain some warmth even when wet. The synthetic-fill technology is nearly there in terms of its warmth when compared to down, but you will pay a weight and bulk penalty for a synthetic-fill bag. Plus synthetic fill does not (as a rule) retain its warming characteristics for as long as down does; this writer has a down-fill bag that is now 20 years old and its still just as cosy as when new.
Sleeping bag choice is, like most gear we spend a lot of time using, always going to come down to personal choice – and, of course, budget (especially if you’re fitting out a family of four or more). The best bet when looking for a sleeping bag is to not be shy about testing them in-store – and testing as many as you can. If you have in your mind a rough idea of what shape and fill you’re after, i.e., a semi-rectangular, down-fill four-season/0-degree bag, that will cut down the time you need to choose the right one.
In terms of what to look for: an effective hood design (it will keep that warmth inside the bag, rather than being lost through your noggin); durable zips; sufficient fill; neck collar (for even more heat retention); sufficient fill (don’t skimp on this); efficient cut (figure out which you prefer: semi-rectangular or mummy).
And don’t be afraid to ask as many questions as you can of the store assistants. Most staff in camping and outdoor stores are campers themselves, often with many years of experience, so if you can give them an idea of where you will use the bag and what you ideally want out of it, you’ll be snug as a bug in your bag, enjoying that starlit outback night before you know it.
Sleeping bag pricing will reflect the quality of construction, the quality of the fill (the most important factor), and the shape of the bag; oddly enough, considering they are the ‘smallest’ in form/size, mummy bags will usually be the most expensive, due to their excellent warming qualities.
As a guide, expect to pay from between $250 through to $800 for a sleeping bag of any decent quality. For this outlay you can expect to get a bag that should, with good care and maintenance, last you for a decade or more. As with any specialised gear, the more you pay generally means the more features/better quality. Of course, what you pay will also be governed by where you are going and how much camping you do. For those who venture out twice or three times a year, to eastern seaboard caravan/camping grounds, it may be tempting to opt for one of those cheap $75-100 bag from one of the big camping franchises, but don’t – invariably, the cheapies' zips or fabric will fail, and you may be left suffering through a cold night or two, which is not the memory you want to bring home from a camping weekend.