Comfort
Why wool itches, and how to stop it.
Most "wool itch" isn't an allergy. It's thick fiber ends poking the skin. Choose finer fiber and smoother fabric and most of the problem goes away.
REF-01
The Real Cause: Coarse Fiber Ends
Every wool garment has thousands of fiber ends sticking out of the surface. Fine fibers bend when they touch skin. Fibers thicker than roughly 30 microns are stiff enough to push into it and trigger the nerve endings that register prickle.
- It’s the coarsest fibers that matter, not the average. A yarn with a fine average but a wide spread of diameters can still prickle.
- True wool allergy is rare. Lanolin sensitivity exists, but it's uncommon, and most lanolin is washed out at the mill.
- Dry or sensitive skin notices prickle more, which is why the same sweater can feel fine in summer and itchy in winter.
The numbers behind this are in Merino Micron Standards.
REF-02
Wools Least Likely to Itch
| Fiber | Typical µm | Notes |
|---|---|---|
| Superfine / ultrafine merino | ≤ 18.5 | The safest choice for next-to-skin wear |
| Cashmere | 14–19 | Very soft, but check it isn't a cheap blend |
| Baby alpaca | ≤ 22.5 | Usually soft; no lanolin |
| Cormo | 17–23 | Fine and uniform |
Often prickly: lambswool (it varies a lot), Shetland, Icelandic, Romney and other medium-to-coarse wools. They're beautiful for outerwear and sweaters worn over a shirt.
REF-03
Construction Matters Too
- Tight, smooth knits trap fiber ends better than loose, hairy ones.
- Worsted-spun yarn is combed smooth and prickles less than fuzzy woolen-spun yarn of the same fiber.
- Brushed and napped finishes raise more fiber ends to the surface.
- Collars and cuffs are where you notice it most, so a soft fiber matters most there.
REF-04
Fixes for a Sweater You Already Own
- Wear a layer underneath: a thin cotton or merino base layer is the most reliable fix.
- Conditioner soak: soak in lukewarm water with hair conditioner for about 30 minutes, then press out water and dry flat without rinsing. It temporarily lubricates the fibers.
- A few gentle washes with a wool wash can soften new wool as loose fibers come away.
- Skip the myths: freezing a sweater or soaking it in vinegar is often suggested, but there's little evidence either makes coarse fiber feel finer.
If wool causes a rash, hives or swelling rather than a prickle, stop wearing it and talk to a doctor; that's not a fiber-diameter problem.