Micro Fleece vs Polar Fleece: Learn the Difference.

micro fleece vs polar fleece

Warm. Dry. Comfortable. Light. You want your mid layers to do it all. You demand the very best from your clothing, especially on expeditions and adventures. Cold and wet are not words we use to describe marvelous adventures.

Choosing the right sweater can be tricky, though. Manufacturers throw around product names and want you to choose micro fleece vs polar fleece. What do these words even mean? Let us help you choose the best fleece for your ambitions.

What is synthetic fleece?

Synthetic fleece is a material created in the late 1970’s by the company now known as Polartec. It is created by knitting a standard polyester fiber in a special way. The knitting, napping and shearing process produces the ‘fuzzy’ feeling we associate with fleece. Garments produced like this are lightweight, have excellent insulating ability and are hydrophobic. Hydrophobic means they repel water naturally to some extent.

light brown fleece fabric
Light brown fleece fabric | Efraimstochter

Production methods

How does plastic turn into something soft, toasty, and plush? A few different ways of producing this cozy clothing are used. There are two big categories of production – original and recycled. These two have a few things in common. Here is a basic rundown of the production process:

  1. Acid and alcohol are reacted together in a vacuum to create polymers which turn into raw chips of ‘raw polyester.’ Recycled polyester is made by breaking existing plastic into the raw chips.
  2. The chips are melted and then spun into long fibers. Spinnerets collect these fibers to prepare them for the next step.
  3. The fibers are stretched up to five times their original length and are ready to use.

Those three steps are the basic form of manufacturing polyester fabric. Manufacturers then treat, knit, and nap their fabrics to make them into micro and polar variations. It’s important to understand all polyester is created in the same way up to this point.

Original polyester production is the creation of polyester from scratch. Recycled manufacturing involves melting used plastic, usually from bottles, to convert the plastic back to the raw chips needed for polyester. Polartec’s Repreve is an example of a fleece made by recycling plastic bottles.

Weight categories

What about different kinds of fleeces? Well, here is where buyers need to beware. Retailers and manufacturers are not charities. They want your money! So, they create these product names and descriptions to appeal to buyers. The basic truth is simple:

Micro and polar forms are the same fabric woven at different weights.

Polartec created the first product categories in a clear, unambiguous manner. They classified their fabric by its weight. One square meter of the fabric was weighed. The result determined its ‘weight category.’ The three beginning categories were 100gsm (grams per square meter), 200gsm, and 300gsm. Polartec called its 100 gsm fabric micro.  Today, the categories and names have become complicated and are influenced by marketing demands rather than facts. However, micro tends to describe the lightest and polar usually indicates the heaviest.

woman taking photo outside
Woman taking photo outside | Charles DeLoye

Micro fleece vs polar fleece – the same but different

As we’ve just mentioned, the different weights are all created in the same basic way. The way the fibers are formed affects the performance of the garment as well. Manufacturers are creating new fibers and production methods constantly. Yet these all have the same basic process we outlined above. They are the same but a little bit different. A simple guide to these fabrics may help you understand more. The guide points out one key idea: the goal of the garment determines the choice of fabric.


All polyester fabrics are naturally hydrophobic. Polyester yarns all possess this quality. This means they will resist absorbing water. Water will make its way through the garments, especially when it’s being blown by wind. However, polyester tops are still a good lightweight layer for keeping you comfortable in a light shower.

Because these fabrics are hydrophobic, they also dry very fast. This is their biggest advantage over wool or cotton. A wool sweater might be a bit warmer than a similar fleece sweater. The wool sweater may even have slightly better water resistance. However, wool takes ages to dry out once it gets wet. Not so with polyester garments. You can wring them out, put them back on, and they will dry out in a very short time.

In addition to being resistant to water and quick to dry, manufactured fabrics are also breathable. Breathability is a marketing term thrown around a lot these days. It refers to the ability of a fabric to let moisture vapor pass through it. There are several tests of breathability used in the market today. What all of them show is fleece fabrics are highly breathable – mainly because they are not waterproof.


Let’s move on to the differences between micro fleeces vs polar fleeces. There are three main differences and all of them come from the same change: garment weight. Micro fabrics are 100gsm or less. Polar textiles are generally 300gsm or more. Put simply, they are different because they weigh different amounts.

With the change in fabric weight comes a change in flexibility. As you would expect, a thicker fabric is less flexible than a thinner fabric. Micro garments have weights similar to T-shirts and they are just as cozy and flexible. Polar outfits weigh more and so they bend less easily.

The final big difference is cost. The cost differences are very hard to quantify and generalize. This is because manufacturers and retailers finish fabrics and garments differently. If you compare two identically finished fabrics of different weights, the thinner one is going to be cheaper. However, performance clothing now favors lighter fabrics with technical finishes. These are more expensive than heavy fabrics without the fancy coatings.

A wearer’s guide

Lighter fleeces are ideal for two or three season wear. They are super light, breathe very well, and provide excellent insulation. A typical outfit might start with a T-shirt base layer made of cotton or stretchy fabric such as lycra or spandex. On top of this, a micro layer provides necessary warmth for chilly mornings and autumnal evenings. Finally, a loose, waterproof shell jacket will keep out the wind and rain.

For those venturing out in the cold, the same base layer is important. Next to the base layer, a polar warmer will supply a lot of insulation while avoiding trapping too much moisture next to the skin. A proper parka or winter jacket finishes out a three-layered cold weather suit.

purple fabric with zip
Purple fabric with zip | music4life


There are alternatives to fleece. Some people have allergic reactions to fabrics and suffer from textile dermatitis. Other people are concerned about the environmental impact of wearing – and especially washing – polyester. Modern technology and traditional production have come together to create many alternatives if you have either one of these concerns.

Environmental concerns

Before we mention the alternatives to fleece, we can do our bit for the environment by spreading a little knowledge. These fabrics suffer in the wash. The washing and drying cycles take a real toll on the garments. Patagonia did a study on this and discovered washing jackets, sweaters, and other outdoor apparel releases microfibers into the water supply.

Other environmental concerns, such as the effect of dyes and chemicals used in the finishing of garments, are gathering increased attention.

On the other hand, manufacturers such as Polartec are recycling plastic bottles to create new clothing. As science progresses, more of the damaging effects of clothing production may be offset by new innovations.

Other buying options

If you have one of the concerns we mentioned, then we have a short list of alternative choices for you. Greenchoices.org has a long list of sustainable and eco-friendly fabrics you can choose from. Here is a selection from their list:

  • Organic cotton – Cotton has been used to make clothes for centuries. Modern organic practices greatly reduce or eliminate the use of harmful pesticides and fertilizers. Organic cotton is also likely to be free from damaging dyes and bleach.
  • Hemp clothing – Hemp has also been around for ages. Wooden sailing ships made extensive use of hemp ropes, for example. Hemp produced for clothes is soft, breathable, and great for casual clothes.
  • Linen – Another traditional garment choice being revived in the modern market is linen. Linen has long been known for its softness and breathability. This is a classic summer fabric.
  • Organic wool – Wool is going through a transition similar to cotton. Farmers and manufacturers are producing organic wool. This usually means wool free from pesticides and sourced from sheep raised in a friendly, humane manner.

One of these options is sure to match your needs and fashion choices. Thankfully, you aren’t confined to one choice. Wool might be a great option for the winter months. Linen really comes into its own in the summer.

The winner is…

The goal of the garment determines the choice of the fleece. Which one is best for you? It really depends on what you want to do with it. While micro fleece vs polar fleece is a distinction made by retailers, you can use these terms to guide you towards lighter or heavier fabrics. Here is a little buyer’s guide for you with a few points to consider:

  • Lighter fleeces make great layer options just above your base layer. They provide excellent insulation without sacrificing too much breathability.
  • Heavier fleeces are a great choice above your base layer and beneath a waterproof shell for cold weather.
  • Performance garments mix the terms a bit and confuse many buyers. However, the science is clear: thicker, heavier fabrics provide more insulation.

Buy the best you can afford from a reputable brand such as Patagonia, Polartec, or Columbia. Their clothes will almost certainly be well-made and last for a long time. Be savvy and you will be the real winner.

Featured image src: Rolls of fabric | PIRO4D

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