The Fiber Guide
What each fiber is, how it behaves against the skin, and why we chose it.
Almost everything that decides how a knit feels and how long it lasts is settled before it is knitted — in the fiber, and in the two or three numbers nobody prints on the label.
Every chapter answers the same four questions: what the fiber is, how to tell good from bad, what it’s right for, and how to keep it.
The chapters run in the same order as the Care Guide. What a fiber is, and how to keep it, are one page apart.
Where our fiber comes from and who audits it is a separate account. That one lives on Our Standards.
Cashmere
Warmth without weight, and it improves with age.
What it is
Cashmere is the fine undercoat of the cashmere goat — the soft layer beneath the coarse outer hair that carries the animal through a winter on the Mongolian plateau. Every spring it sheds and is combed out by hand. A goat yields a few ounces of usable down a year and a sweater takes the yield of several, which is the honest explanation of what cashmere costs.
The hollow fiber is the one they take out. Cashmere is often described as hollow. It isn’t. Cashmere down is solid — non-medullated — and that is part of the definition: to be sold as cashmere in the United States it must average no more than 19 microns. The hairs that are hollow are the coarse guard hairs from the outer coat, and dehairing exists to remove them. Leftover guard hair is what makes cheap cashmere prickle.
Why length matters as much as fineness
Two cashmeres can measure the same micron count and behave nothing alike. Long fibers stay anchored in the yarn; short ones work loose under friction and gather into pills. A very fine, very short cashmere makes a superb first impression and a disappointing second winter, which is why fineness alone is a poor way to buy.
Baby cashmere
A few styles are made in baby cashmere: 13 to 14 microns, staple 34 to 36 mm, from a kid goat’s first combing and gathered once in the animal’s life. What you feel is roughly a micron and a half. That sounds like nothing and isn’t — fiber bends more easily as diameter falls, so the drop registers as a knit that moves and settles rather than sits.
Warmth you don’t feel the weight of — crews, turtlenecks, scarves, anything worn against the skin, anything you want to travel in.
It is the wrong fiber alone for a piece that has to hold a hard shape, for heavy abrasion, or for real heat. That is what merino, cotton, and silk are for, and it is why we blend them in where the garment asks for structure or for a lighter, cooler season.
- Comes from
- The combed undercoat of the cashmere goat
- Fineness
- 14–19 µm; 19 is the legal ceiling. Ours run 14.7–15.4
- Best at
- Warmth at almost no weight; next-to-skin softness
- Weakest at
- Holding a structured shape; heavy abrasion
- Care
- Dry clean; fold, never hang
A cashmere fiber is roughly one-sixth the diameter of a hair from your head. That is the entire reason it can be warm without being heavy, and why it lies flat against the skin instead of standing off it.
Cotton
The oldest fiber in the wardrobe, at its longest.
What it is
Cotton is graded by staple — the average length of the fibers in the boll. The upland cotton that makes up most of the world’s crop runs about an inch. Supima, the American extra-long staple cotton we knit with, runs 1.375 inches and up.
Those fractions do the work. Longer fibers spin into yarn with fewer ends poking out of the surface, and fewer loose ends means a smoother hand, more even dye uptake, and far less to give up to friction. Pilling, fading, and thinning at the elbow are all consequences of short fiber. Buying long fiber is the cheapest durability there is.
Pima and Supima
Pima is the cotton — the extra-long staple species Gossypium barbadense. Supima is the same species under a trademark, licensed only where the fiber is 100 percent American-grown ELS Pima. Nobody owns the word “pima,” so nobody audits it; a Supima claim is licensed and forensically tested. How that testing works.
Cotton breathes in both directions: the fibers trap air, so a cotton knit insulates in cool weather and sheds heat in warm. It is also what we blend into cashmere to carry a knit through spring and summer. It takes up close to a fifth of its weight in moisture before it feels damp, and it doesn’t hold odour, so most cotton pieces need airing rather than washing.
Its weakness is recovery. Cotton has little natural spring — stretch it and it tends to stay stretched. It shows up worst in loose, open knits, where the structure itself offers no resistance and the fabric drops under its own weight. That one limitation is the reason for most of the blending we do.
- Comes from
- Supima — American extra-long staple cotton
- Staple
- 1.375 in. and up, against roughly 1 in. for upland
- Best at
- Year-round wear; breathing in both directions
- Weakest at
- Recovery — it stretches and stays stretched, worst in loose gauges
- Care
- Dry clean; washable cold with care
Linen
The one fiber that gets better in your hands, not ours.
What it is
Linen is spun from flax — not from a boll or a fleece but from the stalk of the plant, which is why it behaves so differently from everything else here. Bast fibers are long, straight, and strong, and they move moisture away from the skin faster than cotton. Ours is woven in Belgium by a family mill working flax since 1858. Where it grows and who weaves it.
Why it starts stiff
New linen has a crispness that reads, wrongly, as coarseness. Flax fiber is stiff until it has been flexed, and every wash breaks it down a little further. A linen shirt at five years is a different garment from the one you bought, and better. It is the only fiber we sell where the instruction is genuinely use it more. The creasing isn’t a defect either — linen holds the shape of the day you spent in it.
Heat, and anything you want to look lived-in rather than pressed. Linen is stronger wet than dry, which is why it survives washing better than almost anything else in the drawer.
It is the wrong choice where you need a crease-free surface all day, or close-fitting recovery. Flax has almost no elasticity — that is what the wrinkles are.
- Comes from
- Flax stalk; woven in Belgium since 1858
- Best at
- Heat. Moves moisture faster than cotton
- Weakest at
- Elasticity — it creases, and it is meant to
- Improves
- With every wash, for years
- Care
- Dry clean; cool and gentle at home
Denim
The only fabric we make that keeps a record of you.
What it is
Denim is cotton woven as a twill — the weft passing under two or more warp threads at a time, which produces the diagonal ridge you can see in raking light. Only the warp is dyed indigo; the weft stays undyed. That is the whole trick, and it explains everything denim does: the pale underside, the deep face, and the way colour lifts at the knee and the hip before anywhere else.
Why it fades where it does
Indigo doesn’t penetrate the cotton fiber. It sits on the outside of the yarn and wears off with abrasion, taking the surface with it. Every crease that folds the same way each day loses colour faster than the cloth around it. Given a year or two, a pair of jeans carries a map of how their owner sits, stands, and carries a phone — and the fabric only does this if you leave it alone.
Repetition. Denim is the one thing in a wardrobe that improves specifically because you wore it and didn’t wash it, and heavier weights mold to the body in a way lighter ones never quite do.
It is the wrong fabric if you want it to look the same in year three as it did on day one. That is not what denim is for.
- Comes from
- Cotton, woven as twill; indigo on the warp only
- Best at
- Wearing in. It records how you move
- Weakest at
- Frequent washing, which is what kills the fade
- Care
- Dry clean; cold and inside out at home. Wash seldom
A blend is a problem being solved
Most people read a blend as dilution — cashmere cut with something cheaper. Sometimes that is exactly what it is. But every fiber on this page has one thing it does badly, and the honest use of a blend is to hand that job to a fiber that does it well.
Here is what each addition is actually for, so you can tell the two apart on any label, ours or anyone else’s.
Acrylic
Two things compound here. Cotton has almost no natural spring — stretch it and it tends to stay stretched. And an open, loosely tensioned knit is the structure least able to help: there is air in the stitch and little friction between the loops, so the fabric has nothing holding it but the yarn’s own memory.
Put those together and a loose cotton knit drops. It lengthens through the day, the front edges grow, the neckline widens, and washing only resets some of it. The looser and more open the gauge, the faster it happens — which is exactly the kind of knit people reach for in warm weather.
A share of acrylic supplies the memory the cotton doesn’t have. The fabric returns to shape after wear and after washing, and the colour holds without the chalkiness cotton can take on. Wide ribbing at the cuffs and hem does the same job structurally; the acrylic does it at the level of the yarn, everywhere at once.
In our Open Cardigan (CB002) and Round Edge V-Neck (CT006) — both deliberately loose, open knits with nothing to close them and a long body carrying its own weight. The pima cotton is what you feel against the skin; the acrylic is why the fronts still hang straight and the hem is still where you left it a year in.
Cotton
Cashmere’s difficulty is that it is very good at one thing. In January that is the whole point; in April it is the problem. An all-cashmere knit in warm weather is simply too much insulation, and the fiber doesn’t move moisture the way a summer garment needs to.
Cotton fixes both. It breathes in two directions and takes up close to a fifth of its weight in moisture before it feels damp, so a cotton-and-cashmere knit can be worn into spring and through a warm evening without the heat of pure cashmere — while the cashmere keeps the hand, which is what an all-cotton knit never quite has.
Cotton and silk are not the same solution. Silk lightens the yarn and improves the fall — it makes cashmere lighter. Cotton changes how the fabric handles heat and moisture — it makes cashmere cooler. A spring knit using one is a different garment from a spring knit using the other, and the label will tell you which.
Silk
Silk filaments are long, smooth, and triangular in cross-section, so they catch light and slide against each other rather than gripping. Blended into cashmere they lighten the yarn and let a knit fall instead of holding its own volume.
It is what carries a cashmere piece into spring without losing the hand.
Merino wool
Fine merino sits close to the cashmere ceiling on fineness but behaves quite differently — it has natural crimp, so it springs back, holds a rib, and insulates even when damp.
Blended into cashmere it buys shape retention in the places a garment is asked to hold a line: collars, plackets, anything tailored.
Elastane
A few percent at most, and almost always in denim or a close-fitting knit. Elastane is what lets a waistband or a cuff return to size rather than settling a little larger each wear.
The tell of a bad blend is quantity. Past roughly five percent in denim the fabric stops behaving like denim and starts bagging at the knee, and the fade never develops properly.
Nylon
Where a garment takes concentrated wear — heels, toes, elbows — a small proportion of nylon carries the friction that would otherwise thin the natural fiber. Used sparingly and in the right place, it is the difference between a sock that lasts a season and one that lasts years.
Ask what the second fiber is doing. If it solves something — recovery, abrasion, drape, structure — and it is present in the proportion that job needs, it is engineering. If it is there in large proportion with no job you can name, it is there to lower the cost of the yarn.
Proportion is the tell. Two percent elastane is a fit decision. Thirty percent of anything is a price decision.
Recycled and lower-impact fibers
Where a manufactured fiber genuinely earns its place in a garment, we look first for a recycled or lower-impact version of it before a virgin one. We would rather say less here than claim a certification we cannot show you.
The other fibers we use
Each appears in blends or in single styles. Each follows one of the four care chapters above — noted alongside.
Wool
Merino from Australia, lambswool spun in Yorkshire, extra-fine merino from Italy. Fine merino sits around 19 microns — close to the cashmere ceiling, which is why a good merino is nothing like the wool most people remember from childhood. It holds structure better than cashmere and insulates when damp, so it does the work in pieces that need to keep their shape. Judge it on: micron count and crimp. Fine merino should spring back when you crush it in a fist.
Yak
Combed from herds on the plateaus of Qinghai, Tibet, and Sichuan, and warm in the way an animal living above four thousand metres requires. Naturally anti-microbial, notably strong for its fineness, and it comes in the deep browns and greys of the animal, so much of it never needs dyeing. Judge it on: whether the colour is natural or dyed — undyed yak is the point of it.
Alpaca
Bred in South America for more than five thousand years. Very fine — the top grades are sorted as royal and super royal — and unusually durable for its softness. Warmer than wool at the same weight, with a heavier drape. Low in the proteins that trouble people who react to sheep’s wool. Judge it on: halo. Good alpaca has a soft bloom; a hard, wiry surface means coarse grades.
Silk
Filaments triangular in cross-section, which is why silk catches light the way no other natural fiber does. Strong, breathable, cool to the touch. In a cashmere blend it lightens the yarn and improves the fall. Judge it on: lustre that shifts as you turn it. A flat, even shine is usually a synthetic imitation.
Acrylic
The one fiber here that isn’t natural, and we use it deliberately rather than apologetically. It goes into our loose, open cotton knits — the gauge with the least structure of its own — where it supplies the recovery cotton lacks: shape memory at the front edges, the hem, and the neckline. Judge it on: proportion and placement. A minority share doing a named job is engineering; a majority share is a price decision. See Why we blend.
What Really Matters.
Client CareNot sure which fiber a piece is, or how a blend should be handled? Every note is read and answered personally.