Polartec Fleece Fabric - How Fleece Revolutionized the Outdoor Industry

What is Polartec Fleece?

The story of fleece began with the invention of synthetic fibers in the mid-20th century. It was during this time of innovation that Malden Mills, now known as Polartec, made a significant breakthrough by developing an easy-care alternative to wool. In the late 1970s, Aaron Feuerstein, the CEO of Malden Mills, spearheaded the development of this new fabric that would revolutionize the outdoor apparel industry. Drawing inspiration from natural wool, Feuerstein and his team were experimenting with different ways to knit polyester yarns and stumbled upon an unusual lofty style that had some amazing characteristics.   They branded this unique fabric as "Polar Fleece

How is Polartec Fleece Made?

Polymer Extrusion:

The process begins with extrusion of polyester or blends that are forced through spinnerets to create long continuous fibers. Polartec Fleece is mostly made with recycled PET (polyethylene terephthalate). The long fibers make it non-pilling which is why Polartec Fleece is so luxurious and looks great for many years. 

Spinning and Stretching:

Once extruded, the fibers are cooled and solidified. They are spun and stretched to align their uniformity and improve strength. 


The extruded yarn is then knit using specialized knitting machines.  Polartec Fleece comes in hundreds of styles and each of them have different processes. But the majority are knit using a double-sided technique with produces a very plush, napped surface on both sides. 


After knitting, the fabric undergoes many treatments to enhance its performance including brushing to raise the nap, shaving the nap to a desired height, or creating a variety of designs such as shearling, for example.  Other treatments to make it water repellent may be added.


Polartec Fleece is dyed in hundreds of colors either by piece dying or yarn dying.  All fabrics produced by the Polartec Mill are by special order, and often the styles are not available to the public.  They may be controlled styled reserved for military, for example. 

Quality Control:

Many tests are performed to determine that each production of Polartec Fleece meets high standards.  They test for thickness, density, softness, durability, strength, colorfastness, abrasion resistance and many other performance characteristics. 

What are the Benefits of Polartec Fleece

The Qualities of Polartec Fleece Make it the Best.

Density and Thickness

Polartec Fleece is denser than the lower quality fleece you will find in most fabric stores. However, it comes in so many weights and styles that its hard generalize. If you look just at the category of Polartec 200 weight fleece which is typically the midweight version you would use for jackets or blankets, it almost needs to be handled to appreciate how scrunchy, dense and soft it is.  Once you feel the loft of Polartec Fleece it is apparent how dramatically different it is from cheaply made knock-offs. 

Fast Drying

One of the benefits of Polartec Fleece over wool is the ability to dry very quickly. This makes it a great mid layer such as a vest or hoodie under a breathable shell, as well as a perfect spring/summer jacket fabric.


 Polartec Fleece is made to last. I have a couple of jackets I made around 20 years ago and other than the color isn't my favorite anymore, they look like new despite being worn hundreds of times.  Quality pays, and Polartec Fleece is a great example. 

Environmental Impact

Polartec uses a lot of recycled materials in their fleece lines. This can range from used pop bottles to discarded clothing.  Incorporating recycled fibers is only one part of minimizing the impact on the planet. When a garment lasts much longer, you are less likely to replace it. 

Also, there are many new technologies developed by Polartec that reduce fiber shedding. One such fabric is Polartec Power Air.  Polartec Power Air encapsulates the fleece inside 2 knit layers so it offers the warmth of fleece by trapping body heat, but the fleece fibers are not exposed to the surface and cannot shed. 

How Warm is Polartec Fleece?

Warmth and Comfort

 One of the hallmarks of Polartec Fleece is the exceptional warmth-to-weight ratio.  Despite being lightweight and breathable, Polartec Fleece provides excellent insulation, trapping heat close to the body to keep you cozy. Its great for lounging at home or wearing on a hike! Typically, the loftier the fleece, the more warm body air gets trapped and the warmer the garment. 

Shown to the right is a shearling style of Polartec Thermal Pro Fleece.  This style is considered to be extremely warm. It replicates the heat-trapping style of lambs wool. 

There is no accurate rating for the warmth of fleece, or any other fabric for that matter. A person's metabolism, the temperature, and the activity they are doing all contribute to the warmth they feel, or the comfort level they require.  I can assure you that my spouse thinks our house is warm when I am freezing!  

How do I wash Polartec Fleece?

Another advantage of Polartec Fleece is its ease of care.  Unlike natural fibers such as wool which requires special handling, fleece is machine washable and dries quickly.  Machine wash in mild detergent with no fabric softener! Fabric softeners can degrade the performance over time. It can be machine dried with non-fluffy items (no towels, please!)  I prefer to hang dry as it takes so little time to dry and does not attract fluff from other garments.  

Polartec Thermal Pro Shearling Fleece

Conclusion:  The Enduring Appeal of Polartec Fleece


 From its humble beginnings as a synthetic alternative to wool, fleece has evolved into a functional yet fashionable fabric.  There are so many things that can be made with Polartec Fleece.  Jackets, pants, vests, hats, hoodies...the list goes on.  Dog Coats! 

Polartec invented fleece, and still makes the best fleeces in the world.  There are dozens of styles to choose from, including water repellent stretch fleeces such as Windpro and Windpro Stretch.  Minky-feeling High Loft Fleece, used by major brands for hoodies and jackets.  Thermal Pro Fleeces, which have styles ranging from Sherpa (Shearling) to knit-look dense fleeces.  Lightweight Grid Fleece and Microfleece.  Too many choices! But, thats what we are here for, to guide you when you need to make the perfect fabric choice for your outerwear project! 

Ask for Advice!


There are so many personal considerations when choosing the right fabrics for travel. Choosing appropriate travel clothes depends on many factors. We love to help, which is why we have a Facebook Group. If you ask in our group, be specific about where you are going (climate), what you will be doing and if you plan on packing with carry-on only.  We will try to make suggestions that will fit your trip. We are always happy to chat in the group, where others can learn from the answers! Our Facebook group is Sew Inspired by Discovery Fabrics. Join us! 

Want to make a 

Polartec Fleece Beanie? 

Make a cozy beanie from any of the Polartec Fleece fabrics, with our new Endurance Beanie Pattern!  You can use Microfleece, Windpro Fleece, Grid Fleece or many of the other Polartec Fleece styles. Shown here are several styles of Polartec Fleece, including the amazing Polartec Power Stretch Fleece.  This is a close-fitting beanie, perfect for wearing under a helmet or on its own. The fabric you choose will dictate which season the hat is best for. 

Best fabric for travel tee shirts