Fabric Guide
Boiled wool: knitting that's been shrunk on purpose.
Boiled wool starts as ordinary knitted wool fabric. Hot water, soap and agitation shrink it and lock the fibers together, turning it into a dense, warm cloth that can be cut without unraveling.
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How It's Made
- 01Knit: wool yarn (or a wool-rich blend) is machine knitted into an even, oversized fabric.
- 02Full: the fabric is worked in hot water with soap or another mild alkali and agitated. The wool's scales catch and lock, so the knit shrinks and thickens.
- 03Shrink a lot: the fabric can end up as much as half its original size in each direction, which is why it gets so dense.
- 04Finish: the cloth is dried, sometimes brushed, and pressed to an even width before being cut and sewn.
The name comes from the hot-water treatment, not literal boiling. It's the controlled, industrial version of what happens to a sweater on a hot wash: Felting explains the mechanism.
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Why It's Popular
| Property | Why |
|---|---|
| Doesn't fray | The fulled fibers hold every stitch in place, so edges can be left raw or simply blanket-stitched |
| Wind resistant | The shrunken knit closes up, leaving few gaps for air to pass through |
| Sheds light rain | Dense wool resists water for a while, though it isn't waterproof |
| Warm for its weight | Thick, springy fabric traps air |
| Stretchy and soft | It's still a knit underneath, so it moves more than a woven coat cloth |
| Stable | Having been shrunk already, it's less prone to shrinking further than ordinary knitted wool |
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Where It Comes From
- Old technique: felting and fulling wool go back at least to the Middle Ages, and probably much further.
- Alpine tradition: boiled-wool jackets with simple trim are strongly associated with Austria and the Tyrol, where they're a staple of traditional dress.
- Made worldwide today: boiled wool is produced industrially in many countries, in plain colors and in patterned knits.
- Typical uses: jackets, cardigans, vests, coats, slippers, hats, scarves and mittens.
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Boiled Wool vs. Felt, Loden & Melton
| Fabric | Base | Character |
|---|---|---|
| Boiled wool | Knitted, then fulled | Dense but stretchy; raw edges don't fray |
| Felt | Loose fiber, no yarn | No stretch or grain; can tear if thin |
| Loden | Woven, then fulled and brushed | Alpine coat cloth, traditionally from coarse wool; firm and weather-shedding |
| Melton | Woven, heavily fulled, napped and sheared | Very dense, smooth, classic for coats and jackets |
All four rely on fulling or felting; the difference is whether you start with loose fiber, a knit or a weave. More woven coat cloths are in Woolen vs. Worsted.
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Care
- Air and brush first: like any wool coat, boiled wool often only needs airing and a brushing. See How to Clean a Wool Coat.
- Follow the label: many boiled-wool garments say dry clean or hand wash. Lined jackets are best left to a cleaner.
- Hand wash cool if allowed: a wool wash, no rubbing, no wringing. Hot water and agitation can still shrink it further.
- Dry flat, eased into shape. Never tumble dry.
- Store clean and protect from moths; see Clothes Moths.
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Sewing & Making Your Own
- Cut with confidence: raw edges stay put, so seams can be lapped or butted and edges left unfinished.
- Press with steam through a cloth, and lift the iron rather than sliding it.
- DIY boiled wool: knit or buy a loose knit in untreated (not superwash) wool, then hot wash with agitation, checking often until it reaches the density you want. Swatch first; results vary by yarn.