12 Best Synthetic Insulation Materials for Outdoor Clothing | Vegan Down Alternatives

Last Updated on 06/03/2023

Best Synthetic Insulation Materials

Best Types of Synthetic Insulation for Clothing

In this guide to the best synthetic insulation materials for outdoor clothing, we share 12 different types of synthetic insulation as alternatives to down. You will learn which are the most lightweight and breathable man-made insulation types so that you can decide if it works for your needs.

Synthetic insulation is often used for outdoor clothing like jackets, gilets, gloves, and camping gear like sleeping bags. It offers many benefits that down does not and is a way for vegetarians and vegans to avoid using animal products.

Synthetic insulation has always tried to mimic the qualities of natural insulation like down or wool. It gets fairly close but will never match the warmth-to-weight ratios of down or the durability of wool. Nevertheless, here are some of the best synthetic insulation materials you can choose from today.

12 Best Synthetic Insulation Materials for Outdoor Clothing

Unlike down, synthetic insulation comes in many different varieties. They all do the same thing but may be better in certain areas. Like how  Primaloft has an amazing warmth-to-weight ratio or how eraLoft uses hollow fibers to ensure it works even if wet. Here is a brief explanation of what each insulation claims to do:

Primaloft Synthetic Insulation

Primaloft Synthetic FIll Insulation

Primaloft insulation is used in many of the best ultralight synthetic sleeping bags because it is similar to down. The clusters of synthetic fibers are composed to behave the same way as downy feathers by retaining loft and trapping heat. It works even when wet and compresses down very small with the help of a stuff sack.

After reviewing dozens of synthetic ultralight sleeping bags, Primaloft is constantly one of the highest performers. Here are some of the different types of Primaloft synthetic materials (not including their different eco range).

Primaloft Classic (Black, Silver, and Gold)

Primaloft Classic is available in 3 varieties: black, silver, and gold. Black is the most basic version and as such, provides the least warmth per gram. Silver Primaloft Classic is slightly warmer and more suited for colder but active use. The most expensive of the three types of synthetic Primaloft insulation is the Gold standard which is equivalent to 600FP down and is perfect for very cold conditions where you will still be active.

Primaloft Active

Primaloft Active has improved breathability, stretch, and moisture wicking compared to the Primaloft Classic. It is perfect for lightweight jackets that keep you warm but don’t overheat. Primaloft Active is especially good for insulating the sleeves of jackets so that you don’t get reduced mobility in your arms.

PrimaLoft Black Insulation ThermoPlume

Black Insulation ThermoPlume is Primalofts version of synthetic down, and what makes it so cool is that it can be used in machinery designed for real down feathers. This means that manufacturers can offer synthetic or down fill with any kind of redesigning needed. You simply switch the down-blowing machine to synthetic and fill the baffles as normal.

Climashield Synthetic Insulation

Climashield Apex Synthetic Down

Climashield currently has seven variations of its outdoor clothing insulation, but the best for the warmth-to-weight ratio is the Climashield Apex. Climashield Prism is also very lightweight and keeps its composition and structure under sustained use and when wet. All seven variations use the same microfiber composition, making them some of the lightest wearable insulation.

Climashield Apex Insulation

Climashield Apex claims to be the most lightweight and thermally efficient continuous filament insulation available today. I can’t confirm this, but I do know it sets the bar very high. It also incorporates Aquaban technology to ensure it performs just as well when wet as it does when dry.

Climashield Contur Insulation

Climashield Contur insulation is a slimmer continuous filament fiber that works better for gloves, footwear, and lightweight jackets. It is extra breathable and low profile, unlike a puffer jacket which can feel a little cumbersome when wearing a backpack.

Climashield Prism Insulation

Climashield Prism insulation is designed to be durable and long-lasting for items you use regularly. These are most often jackets and sleeping bags. The insulation can be washed and used multiple times and has been tested not to lose its thermal efficiency like some synthetic downs are guilty of. Prism synthetic insulation also incorporates Aquaban water-repellent technology to ensure high performance, whatever the weather.

Climashield Comfort+ Insulation

Climashield Comfort+ has an extra plush feel to it that is stretchy and quick to warm up. All aspects of comfort were considered, from how warm it is, to how breathable it is or how it feels next to the skin.

Climashield Protect FR Insulation

Protect FR features all of Climashields proprietary thermal qualities and features but with the added benefit of heat flame protection. This makes it a good insulation choice for workwear and camping clothes. We may see some Climashield Protect FR campfire gloves in the future.

Climashield Combat Insulation

Climashield Combat was initially designed for military and tactical use cases. As you might expect, it is incredibly durable, lightweight, packable, and will work whether it is wet or dry. It features Aquaban DWR treatment to help with this.

Climashield Eco Insulation

Climashield Eco is available in high loft and ultra-thin combinations to suit a wide variety of applications for more sustainable outdoor gear. Manufactured from recycled plastic bottles, this is one of a growing number of environmentally friendly synthetic insulation materials for outdoor clothing. 

3M Thinsulate Synthetic Insulation

Thinsulate Synthetic Featherless Insulation

3M Thinsulate is one of the most commonly used insulation for outdoor clothing like gloves, hats, and winter jackets. It is one of the best-value synthetic insulation types for ultralight sleeping bags and doesn’t often feature in higher-end synthetic sleeping bags. Thinsulate is moisture resistant and works even if wet.

Like Primaloft, 3M Thinsulate is its own product that is licensed out to other brands. There are 5 or 6 base technologies that have 4 – 6 varieties of synthetic insulation for each one. Thinsulate also makes water-resistant, flame-resistant, and stretchy 3M insulation.

3M Thinsulate Original

3M Thinsulate Original comes in 4 different varieties known only as Type C, Type M, Type O, and Type P. From what I can understand, they are all made of 100% polyester but in different forms. One has a loose fill which would look more like synthetic down, and another is made into densely pressed sheets of material.

3M Thinsulate Advanced

3M Thinsulate Advanced again comes in two varieties known as Type G, and Type KL. Type G is designed to be incredibly lightweight and soft with high loft. Type KL is much more durable and has excellent moisture resistance and breathability for clothing that NEEDS to be warm.

3M Thinsulate Bedding

3M Thinsulate Bedding insulation is designed specifically for things like sleeping bags and duvet quilts. There are two varieties, including Type TIB, which is the warmer of the two and uses siliconized fibers. The second variety of Thinsulate Bedding insulation is Type Z which uses the same siliconized fibers but is lighter and loftier to mimic down more closely.

3M Thinsulate Featherless

Thinsulate Featherless is 3M’s version of synthetic down. It is super lightweight, fluffy, and efficient for trapping heat. It would be akin to around 500 FP down but with the added benefit of resisting water. There is also a 700FP version of Thinsulate Featherless, which is extraordinarily high. Vegans are quite fond of this type of insulation, and an ECO Featherless version is available too.

3M Thinsulate Recycled

3M Thinsulate Recycled has four varieties. Two of them use the same composition as the featherless insulation but use recycled plastics in varying levels (78% recycled or 100% recycled). The other variations are known as Type EC and Type EP. 3M Thinsulate Recycled Type EP is the warmer of the two and also has a marginally higher recycled plastic content percentage.

Columbia Omni-Heat Synthetic Insulation

Columbia Turbo Down Synthetic Insulation Fabric

Columbia Sportswear has a wide spectrum of thermal insulation technologies under there belt when it comes to outdoor clothing and camping gear. Most of Columbia’s insulated jackets also combine Omni-Heat Reflective technology which is featured further down this guide.

Columbia Double Wall

Columbia Double Wall incorporates a windproof and thermo-reflective outer shell with warm and lightweight synthetic insulation. It doesn’t use Omni-Heat technology but is better than regular nylon or polyester coated with DWR. Some awesome quilted hiking jackets made with Columbia Double Wall aren’t massively warm on their own but are perfect for being active or as part of a layering system.

Columbia Turbo Down

Columbia Turbo Down is a hybrid insulation that uses baffles of natural down backed by a sheet of synthetic insulation. This provides incredible warmth, durability, and performance when active.

There is also an even better version of Turbo Down called Turbo Down Wave, which eliminates cold spots by alternating the alignment of baffles. I bet it is hard to visualize what I mean, so here is a video to explain it:


Columbia Thermarator

Thermarator is a Columbia Sportswear option for synthetic down. Composed of ultrafine fibers that intertwine with each other to form a kind of tangled cluster, it has an impressive warmth-to-weight ratio. Just like down insulation, Thermarator can be stuffed into a baffle for things like sleeping bags or puffer jackets.

Lycra Thermolite Synthetic Insulation

Thermolite synthetic fill for sleeping bags and clothing

Thermolite is made by Lycra and is a family of polyesters that can be used as thin strands to make things like base layers. But the fibers can also be clustered together to create thermal insulation materials for outdoor clothing.

Made from 100% recycled material, Thermolite insulation is EcoMade to reduce our impact on the environment and reduce the amount of plastic going to landfill. The fibers are hollow, so they will work even if they get wet and trap heat very well. There are three main variations as follows.

Thermolite EcoMade Insulation

Thermolite EcoMade Insulation is available in thin and high loft varieties rated with some of the industry’s highest warmth-to-weight ratios. As one of the best synthetic insulation materials, you can expect water resistance, fast drying, lightweight, high thermal resistance, and 85% recycled fibers.

Thermolite EcoMade T3 Insulation

Thermolite EcoMade T3 Insulation is made from just 35% recycled fibers and has improved breathability, is easier to wash, and is slightly more lightweight. But the biggest differentiator is how well it packs down and then recovers to its full loft. The fibers slowly but surely spring back to position even if it has been crushed inside a storage bag all day.

Thermolite EcoMade T-Down Insulation

Thermolite EcoMade T-Down Insulation is a synthetic down and an alternative to natural down jackets and sleeping bags. T-Down has a fill power of 500, but unlike down it will keep you warm when wet, is fast to dry, and won’t clump. Like the T3 insulation, the T-Down synthetic down can pack down very small and then spring back to life when taken out.

Other Thermolite Insulation

Some other products that Lycra has developed are Thermolite EcoMade All-Season Insulation which is designed to insulate you from the sun in summer and the wind and cold in winter. Then there is the Thermolite Infrared Technology which is designed to capture solar heat from the sun as well as trap body heat. Far Infrared Technology is specially designed for socks.

Fjallraven G-Loft Supreme Synthetic Insulation

Fjallraven G-Loft Supreme Synthetic Insulation

G-Loft Supreme is Fjallraven’s own synthetic insulation which they use in some of their jackets, like the Padded Skogso jacket I am currently testing.

G-Loft Supreme is constructed from hollow, fine polyester fibers that naturally form clusters like down feathers do. It is highly compressible, dries quickly, keeps you warm when wet, and can be cleaned regularly without losing performance (unlike down). It can also restore its shape after compression. It is constructed of 10% recycled materials, provides warmth in damp and cold environments, and is made of 10% recycled materials.


The North Face ThermoBall Synthetic Insulation

North Face ThermoBall Synthetic Insulation

ThermoBall is The North Face’s sustainable alternative to down, which uses 100% recycled materials and is incredibly warm, lofty, and compressible. The microfibers mimic the way that down clusters together to create pockets of warm air. The benefit ThermoBall has over down, though, is that it doesn’t all clump together when wet and will continue to keep you warm. One of my favorite North Face ThermoBall products is their camping slipper mules.

Marmot Thermal R Synthetic Insulation

Marmot Thermal R Synthetic clothing and sleeping bag Insulation

Thermal R is Marmot’s own proprietary group of polyester insulation. Using hollow fiber and multichannel filaments, Thermal R is hardly affected by perspiration, humidity, or moisture and continues to trap heat when damp. Marmot also has a sustainable version of the same material that is made using 100% recycled fibers called Thermal R Eco. Both have amazing warmth-to-weight ratios and are very durable for sleeping bags.

Mountain Hardwear Thermic MX Synthetic Insulation

Mountain Hardwear Thermic MC Synthetic Insulation Material

I cannot find much information about Thermic MX, but I remember having a Mountain Hardwear sleeping bag a good few years ago that used this insulation, and it was amazing. It appears that it is no longer being used, but you can still find some vintage synthetic sleeping bags that use it and are still ultralight.

Arc’teryx Coreloft Synthetic Insulation

Arcteryx Coreloft Synthetic Insulation

Coreloft is the insulation of choice for Arc’teryx, who make THE best outdoor jackets in the world. I have never seen a sleeping bag made from Coreloft, but it would absolutely work. It was designed to replicate the properties of down and is one of the most compressible but lofty synthetic fibers out there.

Thermarest EraLoft Synthetic Insulation

Thermarest EraLoft Synthetic Insulation

EraLoft is one of Thermarest’s many innovative products created for camping sleep systems. EraLoft is used in many of Thermarests lightweight synthetic sleeping bags for its ability to withstand being compressed and lofted without losing performance over time. As many synthetic sleeping bag fibers are, EraLoft is spun using a hollow core, which will continue to trap heat even if soaked.

Columbia Omni-Heat Reflective Insulation Synthetic Insulation

Columbia Omni-Heat Reflective Insulation

Omni-Heat, made by Columbia Sportswear, has around five different varieties that all use the same idea at their core. What makes Omni-Heat different is that it is designed to be used alongside other types of insulation, which may include down. Their industry-leading reflective technologies incorporate the qualities of thermal blankets to maximize the amount of body heat trapped.

Omni-Heat Infinity

Omni-Heat Infinity is the most reflective and warm synthetic insulation made by Columbia Sportswear. It uses gold circles of reflective material dotted across the lining so that it remains totally breathable. These dots reflect body heat all day long but also mean that your jacket feels warm just seconds after putting it on.

Omni-Heat Black Dot

Omni-Heat Black Dot is the world’s first external thermal shield which uses the same circular patch design as the Infinity, just on the outside. The idea behind the black dot is to capture any solar heat when the sun shines as well as reflect any warmth trapped within the insulation.

Omni-Heat 3D

Omni-Heat 3D uses a unique pattern that combines the reflective lining with small dots of soft fibers that help improve insulation and next-to-skin comfort. You may find Omni-Heat 3d on the lower back section of a ski or snowboard jacket, which doesn’t give you a cold shock as you sit down on a ski lift.

Omni-Heat Reflective

Omni-Heat Reflective is the standard or original version of the synthetic insulation fabric. It uses small silver dots to reflect body heat back to you without losing breathability. It is lightweight but very warm.

Omni-Heat Thermal Coil

Omni-Heat Thermal Coil is the lightest of all the varieties and suitable for mild and cold conditions. It doesn’t use the same dots or 3D design but instead coils in continuous lines.

Thanks for reading this guide to the best synthetic insulation materials.

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Gear Assistant

This article has been written and/or edited by Andrew N. 20+ years of hiking, mountaineering, and camping experience, with access to all the latest outdoor gear.

  1. […] pass, so they can’t be too tight or baggy. I like ski gloves that feel snug and packed with synthetic insulation, with my fingertips pretty close to the […]

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