What Is Wool Felt? Warmth, Rain, Shrinking and Non-Mulesed Wool

The short answer: wool felt is a dense fabric made by matting wool fibres together with heat, moisture and friction, with no weaving or knitting. It is warm, breathable and holds its shape, and it sheds light rain, but it is not waterproof. Heat, soaking and rubbing make wool shrink, so never wash or tumble-dry a wool hat.

Most of our cold-weather hats are wool felt, and Bill Conner has been shaping felt hats in Byron Bay for over 50 years. Here is what wool felt is, how it handles rain and warmth, why it shrinks, and what "non-mulesed Australian wool" means.

Shown: the Jackeroo Crushable Wool Outback Hat in Brown.

What is wool felt?

Felt is one of the oldest fabrics there is. Britannica defines it as fabric "obtained through the interlocking of wool, fur, or some hair fibres under conditions of heat, moisture, and friction." The fibres are combed into loose layers, then steamed and pressed until they lock together. A final stage called fulling shrinks the felt by "as much as 50 percent", making it dense and strong.

A felt hat starts as a soft cone or "body" of felt. It is steamed and shaped over a metal hat block to set the crown and brim. Many of our wool hats are made crushable, so they spring back after being packed; others are stiffened on purpose to hold a crisp western or fedora shape. Felt-making itself produces very little waste.

Wool felt vs other hat materials

Is wool felt warm?

Yes. Wool traps air between its crimped fibres, and it handles sweat well. The Woolmark Company reports that wool "can absorb up to 35% of its weight before feeling wet and clinging to the skin." So a wool felt hat stays comfortable on a cold morning without turning clammy when you warm up on a hike.

For cold days, look for a deeper crown and a brim that blocks wind and drizzle. The Aussie Wool Crusher Hat has a 3" brim and a 4.5" crown, and it is crushable, packable and water-resistant. See every cold-weather style in our winter hats.

Is wool waterproof?

No. Wool is water-resistant, not waterproof. Woolmark explains that each fibre's outer layer is made of overlapping scales, like roof shingles, that "repel moisture like light rain." Felt is dense, so a wool hat sheds a shower well. In a long downpour, though, water eventually soaks in.

That is why we describe our wool hats as water-resistant. The Quincy Water Resistant Wool Gambler, for example, has a 3" brim and a 4.25" crown, and it is crushable for travel. If you need a hat that is truly waterproof, choose oilskin or waxed cotton: the Northern Front Oilskin, the Mountain Trail Waxed Cotton or the Portland Waxed Cotton Rain Hat.

If your wool hat gets soaked: shake off the water and blot it with a towel. Reshape the crown and brim by hand, and let it dry naturally away from heaters, fires and direct sun. Once it is dry, brush it and use kettle steam to touch up the shape.

Does wool shrink?

Yes, if it gets hot, wet and rubbed all at once. Woolmark explains why: "When exposed to heat and moisture the scales lift and with mechanical agitation start to lock onto the scales of other fibres in a ratchet-like mechanism. This process is irreversible."

That is the same process that makes felt in the first place, so a felt hat can keep shrinking if you treat it like laundry. Rain and everyday wear are not the problem. The damage comes from a washing machine, hot water, a tumble dryer, or drying it on a heater or a car dashboard.

• Never machine-wash, soak or tumble-dry a wool felt hat.
• Spot-clean marks with a barely damp cloth and cold water, then let the hat dry naturally.
• If a hat feels tight, it can be gently stretched; it will not loosen on its own. If it feels loose, use the two free size inserts that come with every hat. Check your size on our Hat Size Chart.

Our step-by-step How to Wash a Hat guide covers wool felt and every other material.

What is mulesing?

Mulesing is a procedure used on Merino sheep in Australia to prevent flystrike, a painful infestation by blowfly maggots. RSPCA Australia describes it as "cutting crescent-shaped flaps of skin from around a lamb's breech and tail." The scar tissue that forms is less likely to attract blowflies. RSPCA Australia calls it painful and says breeding flystrike-resistant sheep is the practical way to end it.

What is non-mulesed wool?

Non-mulesed wool comes from sheep that have not been mulesed. Our wool hats are made from Australian wool, and many are made from non-mulesed wool. Setting up that supply took us two years. Since then, our factory has moved to buying Responsible Wool Standard (RWS) wool. Under the RWS, run by Textile Exchange, "mulesing is strictly prohibited." Many of our wool hats, such as the Detroit Wool Fedora, are made in a Responsible Wool Standard (RWS) Certified Factory.

To be clear about what we can and can't promise: the RWS certification belongs to the factory, and wool tracing relies on our suppliers. We don't trace every batch back to the farm ourselves. Browse every style in our non-mulesed wool hats collection.

How long does a wool felt hat last?

It depends on how often you wear it and how you look after it, but felt hats commonly last 10 to 15 years, and a well-kept wool outback can last 30 years or more. The Jackeroo Crushable Wool is a good example of a hat built for years of travel: Australian wool, a 2.75" brim, a 4.5" crown and an organic cotton sweatband, and it packs flat and springs back. When a wool hat body does reach the end of its life, the wool is biodegradable (the inner and outer bands are not).

Shop all wool outback hats, and see our Hat Care page for the full care routine.