Down vs. Synthetic Insulation in Backpacking Gear: Which Is Better?

Thru-hikers everywhere obsess way too much over the most minute of gear decisions. This is a fact. It is also understandable, as hikers gamble their safety and comfort on the few possessions they can fit inside their backpacks.

Among a long-distance backpacker’s few essentials, you’ll likely find items meant to insulate: certainly a sleeping bag or quilt, probably a puffy jacket, and maybe even a pair of insulated pants, booties, gloves, or mittens. For these pieces of gear, hikers must choose between down and synthetic insulation.

If you run cold, like me, your quilt can double as a second jacket for those frigid mornings.

In this article, we’ll do a deep dive into the down vs. synthetic insulation debate, before summarizing the benefits and drawbacks of each. Finally, we will answer the question of which insulation reigns supreme or, at least, which insulation is right for you.

Down Insulation in Backpacking Gear

What Exactly Is Down?

Down refers to the cluster of plumage found beneath the outer feathers of ducks and geese. It looks like a pulled-apart cotton ball thin, fluffy strands that are lightweight, compressible, and breathable. These strands work to trap warm air against your body, keeping you warm in cold environments.

When shopping for down products, you’re typically confronted with two pieces of information: down type and fill power.

Duck Down vs. Goose Down

Down type refers to, shockingly, the type of down used in the gear, with duck and goose down being the most common. The insulation can be made from one or the other, or a mix of the two.

Generally speaking, the clusters formed from goose down tend to be larger and space out slightly better compared to duck down. This allows goose down to trap more air, providing better insulation and warmth per ounce.

Whether this difference in warmth is worth the difference in price, however, is up for debate. The thru-hikes I’ve completed have been with duck down gear, and I’ve never had any complaints about the insulating ability.

down vs. synthetic insulation for backpacking

I have so many pictures of me hanging around outside my tent in my quilt… I just get too cold, too easily.

Fill Power

The fill power number represents the volume in cubic inches that one ounce of down occupies when allowed to reach its maximum loft. The number is found by placing a standardized amount of down into a graduated cylinder and allowing it to expand freely for a specific period of time. The occupied volume at the end of the designated time period determines the down’s fill power rating.

Did your eyes glaze over a little reading that? Yeah, me too. Essentially, fill power directly relates to the warmth-to-weight ratio of down gear, with a higher fill power offering better warmth per unit of weight.

Down Insulation for Backpacking: Pros

Down insulation offers plenty of advantages, if you’re willing to brave the higher price tag.

Warmth: The natural fibers within down trap more pockets of air than synthetic insulation, making down gear better at warmth retention.

Weight: Along with providing better insulation, down weighs less than synthetic materials, making down-filled gear lighter than its synthetic counterparts.

Compressibility: Again due to the larger air pockets created, down gear can compress to a smaller volume than synthetic gear.

Longevity: High-quality down gear, when cared for properly, retains heat and lasts longer than synthetic gear.

down vs. synthetic insulation for backpacking

I’ve had my Hammock Gear quilt (with down insulation) since 2021. She’s still going as strong as the day I got her!

Down Insulation for Backpacking: Cons

Cold When Wet: We’ve just gone on and on about down’s superior insulating abilities compared to synthetic materials. However, all this falls apart in the presence of water. Down, unlike synthetic material, loses its insulating properties when wet.

The plumes get weighted down and clump together when wet, destroying those precious air pockets that normally give down its superior loft and warmth.

Drying Time: Not only does down not work as an insulator when wet, but it takes longer to dry than synthetic gear. We’ll talk more about why later, but just know that maintaining your gear’s insulating abilities in wet or humid environments will be a challenge.

For my first winter ascent of a 14er, I wore my down coat and wondered why it was doing such a terrible job at keeping me warm. I had sweated right through the down, rendering the coat almost useless until I got back home to dry it.

Price: Quality down gear tends to come with a higher price tag compared to synthetic alternatives. You can make the argument than down tends to last longer than synthetic, which may save you money in the long run, but it’s hard to ignore the higher upfront cost that accompanies most down gear.

Maintenance: Down requires very specific care to maintain its performance. Not only do you need a specific type of soap and washing machine to clean down gear, but there is a finicky way you need to dry it in order for the down to stay lofted. It’s time consuming and labor-intensive, and most people don’t have access to the necessary tools while on the trail.


Synthetic Insulation in Backpacking Gear

Synthetic insulation consists of man-made fibers designed to mimic the insulating properties of natural down. Unlike down, synthetic insulation encompasses a far wider spectrum of actual materials, with many brands using their own specific cocktail of fibers. You may recognize popular synthetic fills such as Arc’teryx’s Coreloft or Patagonia’s PlumaFill.

Such a wide variety of insulation can still be separated into two main categories: continuous filament insulation and loose fill insulation.

Continuous Filament Insulation

Also known as block insulation, continuous fill insulation consists of unbroken strands of synthetic fibers woven together to create insulation. While less compressible, its resistance to clumping or shifting provides constant warmth and durability throughout.

Loose Fill Insulation

Loose fill insulation, on the other hand, consists of synthetic fibers loosely distributed within chambers of the gear. The term “loose fill” highlights the ability of these materials to pack down into a small volume when not in use and then fluff up again to provide warmth and insulation when needed.

Synthetic Insulation for Backpacking: Pros

Warm When Wet: Synthetic fill, unlike down, retains its insulating properties while wet. I can think of a thousand ways thru-hikers expose their gear to moisture, ranging from rain and mist to tent condensation and sweat. Being able to trust your gear in damp environments, especially if you’re hiking somewhere wet and humid, is incredibly important.

When I know it will be cold enough for me to want to hike in my coat, I now always wear one made with synthetic insulation, even if the weather isn’t humid.

Quick Drying: Not only do the fibers still insulate while wet, but the gear will also dry out faster than down. This is huge when it comes to comfort, but it also offsets the weight difference between the two materials. While down may be nominally lighter, waterlogged down will absolutely outweigh dry, synthetic gear any day.

Affordable: Synthetic gear is often more budget-friendly than down options, due largely to different manufacturing processes and the limited supply chain for down. While thru-hikers are often looking for ways to trim down their pack weight, I’ve never heard of someone being excited to pay more for their gear.

That being said, there are great budget-friendly down options out there. I bought this Decathalon Forclaz puffy used for under $30.

Hypoallergenic: While uncommon, some people may be allergic to or have a sensitivity around down. Synthetic insulation would be preferable in that situation.

Synthetic Insulation for Backpacking: Cons

Bulk: Synthetic insulation is bulkier and less compressible than down. Anyone who has struggled to shove a sleeping bag or quilt into the bottom of their bag knows the value of compressible gear and synthetic materials can leave something to be desired in that department.

A bear can + a nine day food carry = very limited space in my pack.

Warmth-to-Weight: It all seems to keep coming back to those larger air pockets in down. By comparison, synthetic materials just don’t provide the same level of insulation per ounce. In more temperate environments, this may be fine. In cooler conditions, this may necessitate additional layers and a heavier pack.

Environmental Impact: Synthetic materials are often derived from petroleum-based sources, leading to a larger environmental impact than gear made from ethically sourced down. Although the most environmentally friendly consumption is no consumption at all, it’s important to consider your personal footprint when making your gear decisions.

READ NEXT – Best Synthetic Jackets for Backpacking of 2024

Gear Wars: Comparing Down vs. Synthetic

As long distance backpackers, our time in the backcountry can stretch into days, weeks, and even months. The trust we place in our gear cannot be overstated. Each ounce carried and every inch of pack space becomes valuable, and it is within this context that the debate between down and synthetic gear lives. We’re all just trying to strike the right balance between weight, warmth, durability, packability, and cost.

Let’s break down the flood of earlier information to find a winner in each of these categories.

Warmth-to-Weight Ratio

Down is renowned for its exceptional loft and insulating abilities, and emerges as the victor when it comes to warmth-to-weight ratio. While synthetic fibers work in much the same way to create air pockets and trap warm air, down possesses a three-dimensional loftiness that synthetic insulation has not quite yet managed to replicate. The unique structure of down allows for the creation of larger, and more, air pockets, giving down the ability to retain more warmth per ounce.

Winner: Down

If you’ve ever gone for a long hike … you know that ounces can feel like pounds on the most grueling of uphills.


Once again, the trophy goes to down. Synthetic fibers compress, therefore losing their insulating properties, more easily than down. This issue compounds over time and repeated compression, resulting in a decrease in the long-term performance of synthetic gear compared to down.

Winner: Down

Water Resistance

Here is where down takes a bit of a hit. Unlike synthetic insulation, down cannot retain heat in the face of water. Synthetic gear is typically made from polyester fibers, which are hydrophobic. This means these fibers naturally repel water and don’t absorb moisture, which is not a strength shared by down.

Even when synthetic insulation becomes wet, it continues to hold onto some of its insulating properties, since the fibers don’t become waterlogged. Additionally, moisture evaporates faster from synthetic insulation, allowing your gear to dry faster.

Synthetic wins this category.

Winner: Synthetic

When I’m backpacking on the humid, humid East Coast, I tend to wish I had more synthetic gear.


The different structures between down and synthetic insulation, once again, cause down to win when it comes to compressibility. Down insulation’s strucure structure of many interlocking fibers that both easily compress and regain loft. Synthetic insulation, on the other hand, usually has less flexible fibers and a more rigid structure.

When I’m shoving all my gear in my bag, and trying to fit multiple days of food in there as well, I’m very grateful for how little space my down gear is capable of occupying.

Winner: Down


The existence of this debate, inherently, means there isn’t an easy choice between the two insulation types. While down can boast a superior warmth-to-weight ratio, durability, and compressibility, this comes with a pretty steep price tag.

Synthetic insulation manufacturing costs less compared to the same processes with down. The synthetic fibers can be produced in large quantities, and utilize fairly inexpensive materials and techniques to do so. Down, on the other hand, is incredibly labor-intensive and costly to source, clean, and process.

Winner: Synthetic

READ NEXT – Best Down Jackets for Backpacking of 2024

Considerations for a Thru-Hike

These pieces of gear don’t exist in a vacuum. You take your insulating pieces out into the wilderness, expose them to all kinds of conditions, and have limited resources with which to care for them. Let’s take a look at down and synthetic gear choices within this context, and see if the right answer for you changes.

Gear Type

We can sit here and talk about different types of insulation until our faces turn blue — and it sort of feels like we have! For all the information I can present about the insulation itself, we can’t forget that this insulation is just a small part of the final piece of gear.

So many different things utilize down or synthetic insulation: sleeping bags, quilts, pants, booties, puffies, mittens, and more. The right insulation choice for one of these items may not be the best decision for another. Each piece of gear serves a specific purpose and, as a result, becomes exposed to different conditions and experiences on the trail. Understanding this is key to optimizing performance and comfort across all pieces of gear.

For example, if you like to hike in your puffy jacket, the water resistance of synthetic materials may appeal to you — especially if you’re sweaty, like me. This same consideration probably won’t apply to your sleeping bag, unless you’re someone who experiences horrific night sweats. (In which case, my condolences. Consider a synthetic bag.)

Climate and Weather

This brings us to our next consideration: weather. Is it rainy, muggy, wet, and cold? If so, synthetic insulation may be your best bet. Down doesn’t insulate when wet, so if your gear is going to be soggy most of the time, maybe opt for synthetic.

On the other hand, if you’re traveling somewhere cold and dry, down insulation may be the better choice. I do consider down to be superior in this environment, if you’re OK with the cost.

down vs. synthetic insulation for backpacking

For my upcoming CDT thru-hike, I’ll be bringing largely down gear. I’m anticipating relatively dry conditions, with the knowledge that I’ll have to take extra precautions to keep my gear dry during storms.

On-Trail Maintenance

While down may be naturally more durable than synthetic insulation, it does require a level of care that may be unrealistic for many on a thru-hike. After down gets wet, it can lose its loft and insulation abilities if it’s not dried properly. Typically, this means tossing it in a dryer with a few tennis balls to help break apart any down that has clumped together. Dryers (and tennis balls, for that matter) can be slightly hard to come by in the backcountry.

This also means that washing your down gear, unless you have the special resources, is pretty much a no-go until after your hike. Down may be incredible at insulation, but it does little in the way of odor-resistance. If you know that climbing into a stinky sleeping bag for nights on end, or wrapping yourself in a putrid puffy, is going to really bother you, consider synthetic.

down vs. synthetic insulation for backpacking

When I tell you my quilt has seen me at my worst… I mean it. Look at that hair! When’s the last time you think that girl showered?

Down vs. Synthetic: Which Is Right for You?

Did you click this article hoping I’d actually give you a definitive answer for what kind of gear you should buy? Too bad gear is incredibly personal, with the “right” answer depending on your budget, planned usage, and climate conditions.

In the end, it’s about finding the balance between warmth, weight, durability, ethics, and maintenance. Experiment with different options, listen to other hikers’ experiences, and don’t be afraid to choose different insulating material for different pieces of gear. Essentially, trust your instincts.

down vs. synthetic insulation for backpacking

Personally, I tend to prefer down. But I don’t usually hike in my puffy, and I tend to do most of my backpacking in the arid climates of Colorado. So, for the sticklers who hate a clickbait title, I’ll go ahead and say down is better than synthetic.

Remember, the best gear is the gear that works for you specifically, not what works for anybody else.

Featured image: Katie Jackson photo. Graphic design by Chris Helm.

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