Synthetic versus down for sleeping bag insulation.
There will probably always be a debate in the community on which material is better.
So, which material is better?
Let’s dive in and discuss the qualities of both and then you can decide!
Water Resistance
When it comes down to it, having a dry sleeping bag is always going to be better than a wet one.
Even though technology has helped down sleeping bags become more water-resistant, they still aren’t as effective at repelling water as synthetic bags.
So if you plan to camp in the snow or the weather is looking rainy, a synthetic sleeping bag is the way to go.
Key Takeaway: if you think you’ll run into any rainy weather, or will be canoeing or participating in other water activities (and have to carry your gear with you) during your trip, synthetic bags will be the best option for you!
Warmth
This would’ve been our first talking point as sleeping bags are mostly rated on their ability to keep you warm, but it’s hard to stay warm while your bag is soaked!
For those that are casually camping, meaning your car is only feet away and you don’t have to worry about weight, you can easily find either a synthetic or down sleeping bag that suits you.
If you are going out into the wilderness and want to focus more on carrying as little weight as possible, down sleeping bags are the best option.
Their warmth-to-weight ratio is much better than synthetic sleeping bags can offer.
What Is The Warmth-To-Weight Ratio?
The warmth-to-weight ratio is simply the amount of warmth a sleeping bag can provide for its weight.
This can be measured with the bag’s fill power.
Fill power essentially measures how fluffy (also known as loft) down feathers are.
The way fill power is measured is by determining how many cubic inches one ounce of down feathers can fill inside of a lab container.
For example, a down sleeping bag with a 650 fill power means one ounce will take up 650 cubic inches of space.
With all other things being equal weight (outer material, zippers, etc.), a sleeping bag with a higher fill power will be lighter.
And the higher the fill power the warmer the bag.
If you’re looking for the warmest bag possible, goose down is your best option.
They can achieve a fill power of 900 or higher, whereas the highest duck down goes is in the 750-800 range.
Just make sure you keep in mind the water-resistance when choosing, as a wet bag is not a warm bag!
Key Takeaway: down bags will keep you much warmer than synthetic bags. And for those who need protection from extreme cold, goose down is much better insulation than duck down. Keep in mind that down bags will also have a better warmth-to-weight ratio (provide more warmth while weighing less) than synthetic bags.
Longevity
While the cost upfront is a major factor in overall price, how long a sleeping bag lasts will also influence how much you spend over your camping career.
Because if a sleeping bag is cheaper but wears out and gets ruined faster than a more expensive bag, you will likely be better off purchasing a better sleeping bag in the first place.
When it comes down to longevity, synthetic bags do tend to fare better.
Down sleeping bags contain very tiny feathers which can slip through the seams, resulting in a less-effective insulating bag.
The down material also tends to clump up in the long-term, resulting in cold spots in your bag.
However, the main aspect of longevity is from you, the user.
Taking proper care of any type of bag will help them last much longer.
When you allow contaminants to build up on your bag, they work their way into the insulation and prevent it from providing loft (which traps air to keep you warm).
The longer the contaminants stay on the bag, the harder it will be to regain that loft.
If you follow proper care instructions, you will be able to remove the dirt and oils before they seep into the materials and ruin your bag.
What About For Thru-Hiking Or Long Camping Trips?
Generally you won’t be able to clean your bag while thru-hiking, which means those contaminants we mentioned before will have the chance to build up.
Since there aren’t any real effective ways to clean your bag while you’re on your trek, there’s not too much you can do.
When selecting a bag, it is important to keep in mind that if you will be using them for long trips, they will most likely have a shorter lifespan.
Synthetic sleeping bags are your friend pricewise in this situation, but they are heavier and tend to not fold up as nicely, taking up more space.
Key Takeaway: For those of you who take these long through-hikes, choosing a synthetic bag or a cheaper down bag is your best bet for being the most cost-effective.
Comfortability
Comfortability can almost go hand-in-hand with longevity.
This is due to the fact that a sleeping bag with cold spots will not be comfortable to sleep in, especially if you’re using it in the winter months.
As your sleeping bag ages, the materials inside start to clump up, creating those cold spots.
While this can happen in both types of bags, down bags experience this clumping more frequently.
Synthetic bags are created in two separate ways; short-staple and continuous-filament.
Short-staple synthetic insulation is made up of short strands of filament that is densely packed to help keep you warm.
This helps bags to act much more like a down-filled bag by being more compressible and feel much softer.
The other, continuous-filament, is made with a thicker continuous filament that is much more durable and lofty.
These bags are much stiffer and less compressible, but the form of the bag will last much longer and are much less likely to create cold spots.
Key Takeaway: in the short-term, down bags will be the comfiest, followed by short-staple synthetic bags. However, if you plan to keep your bag around for a while, continuous-filament bags will help prevent cold spots and uneven fill. The choice is yours!
Down-Synthetic Hybrids: Get The Best Of Both
As you’ve probably noticed, each material for sleeping bags has its own advantages and disadvantages.
Manufacturers sought to fix that problem by introducing down-synthetic hybrid bags.
What these aim to do is take the best from each material and combine them to create an all-around great bag.
These hybrids are more water-resistant than pure down bags, will be warmer than pure synthetic bags, and can be found in the middle ground when it comes to pricing.
There are generally two styles for these hybrids; one blends the materials and fills the bag as usual, while the other will have different materials placed in various spots in the bag.
This is usually synthetic fibers in the bottom of the bag and down in the top.
These bags are perfect for those who want one bag for all use types.
However, there are some drawbacks for those that are looking to camp in extremely cold or rainy climates.
Since synthetic fibers don’t bring the same warmth that down feathers do, make sure that your bag is rated for the proper temperatures.
In some cases, you’ll want to opt for down bags to make sure you stay warm.
This won’t likely be as much of a problem as for those who are camping in rainy areas or will be near water.
While the down used is coated to help it stay water-resistant, it is still susceptible to getting soaked.
And down feathers will take much longer to dry out than synthetic fibers.
Since we’re talking hybrids, it won’t be as bad as pure down bags, but it is still something to consider.
Key Takeaway: unless you will need a bag for extremely cold temperatures or will be traveling to rainy areas or will be near water (rafting, canoeing, etc.), a down-synthetic hybrid sleeping bag is likely the all-around best option for you.
Price
Now that we’ve discussed the basics of choosing the correct sleeping bag for you, let’s talk price.
Generally, synthetic sleeping bags will be cheaper than their down alternatives.
And you can usually find the hybrids somewhere in between.
Breaking it down even further, you will usually find that duck down sleeping bags are more cost-efficient than goose down, simply because of it’s availability.
If price is the most important factor for you, I would personally recommend sticking with synthetic sleeping bags.
While they won’t be as warm, they can still get the job done and come in at lower prices.
The next best option(s) will be your low-fill duck down bags or hybrid bags.
If money is not a deciding factor and you can spend a few extra dollars (after considering everything else), high-fill goose down bags will generally run the most expensive.
Key Takeaway: down bags will be the most expensive in the entire selection, with hybrids in the middle and synthetic bags being the cheapest. If price is the leading factor, synthetic bags are the way to go.
Making The Decision: A Recap Of Benefits/Downsides
When looking for a sleeping bag, your choices will be either down, synthetic, or a hybrid.
While the overall warmer and lighter choice is down, if it gets wet you won’t be having a very fun time on your camping trip.
Down sleeping bags will be lighter than synthetic ones and will have a better warmth-to-weight ratio.
However, down bags will also be more expensive, with hybrids in the mid-range and synthetic bags being the cheapest option.
Now that you’ve learned the differences between the insulation materials for sleeping bags, be sure to pick one up that suits you best and go have fun!