By: Orvis Staff

Should you wear a fleece or a wool layer when you head out on your next cool-weather adventure? As you’re pondering which sweater or sweatshirt to grab in preparation, you may well wonder whether fleece or wool promises the most benefits. Which will be most comfortable while providing the best protection from the elements? The answer depends on what the weather’s like and what you’re planning on doing. Is it windy and/or likely to rain or snow? What is your anticipated level of exertion? For example, are you going shopping, or taking a long hike with the dog? All these variables will inform your decision: fleece, or wool?

What Is Fleece—Is it Natural, or Synthetic?

Fleece, also known as polar fleece, is a synthetic fabric made of polyester or a blend, originally invented to imitate wool. During manufacture, the fabric is brushed to give the fibers more volume, making the material soft and “fuzzy” like sheep’s wool fleece (sometimes mimicking sherpa and shearling wool).

What Is the Difference Between Fleece and Wool?

Wool fleece is a natural fiber that covers the skin of sheep and similar mammals, functioning like human hair or other animal fur. The fibers are collected via shearing and processed into the fabric we know simply as wool. Wool has been used for thousands of years to produce garments that keep us warm, including, of course, sweaters. The difference between fleece and wool, generally, is that wool is a natural fabric that comes from animals and fleece is a man-made material.

Which Is Warmer: Fleece or Wool?

Does fleece or wool make the warmest sweater material? Since warmth originates with the heat of your body, a better way to ask that question is, which insulates better: fleece or wool? Both fabrics retain heat effectively in the absence of rain or wind. If you get caught in the rain, wools like Merino provide better insulation, at least initially, because it contains lanolin, a natural water repellent. But once it’s soaking wet, wool takes a long time to dry. Fleece, on the other hand, becomes saturated with rainwater more quickly than wool, making it useless as an insulating layer when wet, but it dries out much faster when you find shelter from the rain.

In general, wool provides better insulation from the wind, unless you wear a fleece with integrated wind-resistant insulation. But if you’re engaged in a high-intensity activity like running, hiking, or biking, this sort of wind-resistant insulation can become too much of a good thing, causing you to sweat—which is counter-productive in cold weather.

Fleece vs. Wool: Pros and Cons

The comfort and performance of both fleece and wool apparel depend in large part on the quality of the apparel. All things being equal, the following is a summary of the pros and cons of wool and fleece sweaters or sweatshirts:

Fleece Pros:

Lightweight

Quick-drying

Easy Maintenance

Fleece Cons:

No insulation value when wet

Can melt near fire

Certain styles may not be breathable

Wool Pros:

Semi water repellent, providing better initial insulation in the wet

Flame retardant

Breathable

Wool Cons:

High Maintenance

Slow-drying

We have many more choices in the modern world than we used to—in just about all realms of life—thanks to technology. Performance clothing is but one example. When it comes to deciding what to wear to keep warm in cool weather, we must no longer settle for clothing that meets some of our needs but not others. Just like ‘there’s a tool for every job,’ there is a warm clothing layer—in wool or fleece— for every occasion.