The short version: There is no official A, B or C grade of cashmere. The legal line, in US labelling rules and the industry’s own definition, is fibre averaging no more than 19 microns. Quality beyond that comes down to fineness, fibre length and honest making — and most of it can be checked in the shop.
Every October the same question comes back with the first cold week: why does one cashmere jumper cost ten times another, when both labels say 100% cashmere? Retailers answer with grades — “Grade A”, “premium Mongolian”, “ultra-fine” — and most shoppers have no way of knowing what those words commit the seller to. The short answer is: less than they sound. This guide sets out what cashmere legally is, what the grading language actually means, and the checks that tell a good jumper from an expensive disappointment.
What is cashmere, legally?
Cashmere is the fine, dehaired undercoat of the cashmere goat, and in the United States the word has a precise legal meaning. Under the federal rules on wool labelling, 16 CFR § 300.19, a fibre may only be called cashmere if it is the dehaired undercoat of the goat Capra hircus laniger and meets three tests. First, “the average diameter of such cashmere fiber does not exceed 19 microns.” Second, the variation in diameter around that average — the coefficient of variation — must not exceed 24%. Third, no more than 3% of the fibre by weight may average over 30 microns.
The Cashmere and Camel Hair Manufacturers Institute (CCMI), the trade association for the two fibres, uses the same three limits in its own definition and specifies the laboratory method for measuring them, IWTO Test Method 8. That is the whole of the formal standard. Nothing in either definition creates a Grade A, B or C.
For perspective, a micron is a thousandth of a millimetre. The CCMI page sets cashmere alongside the wool industry’s “Super S” numbers, where a fabric labelled Super 80s may have a maximum mean fibre diameter of 19.75 microns and Super 250s just 11.25 microns. So the cashmere ceiling of 19 microns sits close to the bottom of the fine-wool “Super” scale, not at some exotic extreme.
So what do Grade A, B and C cashmere mean?
They are a retail convention, not a standard. It is worth being honest about how loose the language is: the Bournemouth menswear retailer Robert Old & Co, which publishes one of the clearer versions of the scale, itself notes that interpretations vary between regions and manufacturers. Its version runs as follows.
One. Grade A — 14 to 15.5 microns, longer fibres, very soft, with minimal pilling.
Two. Grade B — 16 to 19 microns, shorter fibres, slightly less soft, with some pilling.
Three. Grade C — over 20 microns, short fibres that break easily, a coarser feel and significant pilling.
Read that third line against the legal definition. A yarn averaging over 20 microns would not meet the 19-micron average in the US labelling rules or the CCMI definition at all. Some of what is sold as “lower-grade cashmere” is, on these numbers, not cashmere in the regulated sense.
The cashmere brand GOBI Cashmere, in a March 2026 guide written by its director of design development, Uchral Amar, puts the premium threshold more simply: below 16 microns, with long fibres to reduce pilling. Both sources are sellers, and both have products to promote. But they agree on the two variables that matter — fineness and length — and neither can be read off a label in the shop.
What actually decides cashmere quality?
Three things decide how a cashmere jumper feels and lasts: how fine the fibre is, how long it is, and how cleanly it was separated from the goat’s coarse outer hair.
One. Fineness. Finer fibre feels softer against the skin. A compilation on cashmere, mohair and wool fibre by Wini Labrecque, hosted by Cornell University, puts cashmere down at roughly 12.5 to 19 microns, against 34 to 39 microns for adult mohair and 12.5 to 22 for fine-breed wool. The bottom of the cashmere range is what the grading language is trying to describe.
Two. Fibre length. Longer fibres spin into stronger yarn with fewer loose ends, which is why every grading scheme links length to pilling. Labrecque’s figures put cashmere staple length at just 1.25 to 3 inches, against 2.5 to 8 inches for fine wool and 6 to 12 for mohair. Cashmere starts short, so the difference between the longer and shorter end of that range matters a great deal to how a knit ages.
Three. Dehairing. The goat grows two coats: the soft down and a coarser, medullated guard hair, which Labrecque describes as having a hollow core that makes it stiffer. Cashmere has to be separated from that guard hair, and the legal 3% ceiling on fibres over 30 microns is there to keep it out. Poorly dehaired yarn is the cashmere that prickles.
Scarcity is part of the price. Labrecque’s table gives an average cashmere yield of 3.5 to 5.6 ounces, apparently per goat, against 2 to 20 pounds for fine-breed wool. The math compounds quickly: measured against a single jumper, that is a small amount of fibre, and the finest, longest portion of it is smaller still.
How can you check cashmere quality in the shop?
You cannot measure microns with your fingers, but you can check the consequences of fineness, length and making. These are the tests worth running before you pay.
One. Read the composition label first. “100% cashmere” and “cashmere blend” are different products. A blend with wool, silk or nylon is not dishonest, but it should be priced as a blend. Our guide to judging a wool coat in the shop covers how to read fibre percentages on a label.
Two. Look for fuzz before you touch. A knit that already sheds a halo of loose fibre on the rail, or pills at the underarms and cuffs of a shop sample, is telling you about short fibres. Robert Old’s advice is blunt: excessive pilling on any piece signals lower quality.
Three. Stretch a small section and let go. A well-spun, well-knitted cashmere should recover its shape. Fabric that stays stretched or looks thin when held to the light has either little yarn in it or loose knitting.
Four. Feel against the inside of your wrist. The skin there is more sensitive than your fingertips. Any prickle suggests coarse fibre or guard hair left in the yarn.
Five. Ask where it was made and who spun it. GOBI’s own checklist ends with transparent sourcing, and that is the one quality claim you can test by asking. A maker who names the region, the spinner and the knitting workshop has something to stand behind; “premium cashmere” with no detail has not.
Six. Treat softness on the hanger as the weakest test. How a knit feels in the shop says little about how it will feel after a season of wear and washing, which is the softness you are actually paying for.
Is expensive cashmere worth it?
Sometimes, and the price itself is not the evidence. A high price can pay for finer, longer fibre, careful dehairing and dense knitting — or for a logo and a shop on a smart street. The way to tell which is to run the checks above and ask the questions a good maker can answer.
The houses that have built a reputation on cashmere tend to be those that talk about the making rather than the grade. Brunello Cucinelli’s results, which we covered when it raised its growth forecast as logo-led luxury stalled, show what a business built on logo-free knitwear can command. At the independent end, the cashmere line we profiled from Scott Studenberg, built on named mills and a US atelier, makes the supply chain the selling point. Both point the same way: the value is in what can be named and checked.
Where should you buy cashmere?
The four Faz sourcing channels apply, in roughly this order of value.
One. Vintage and estate. Older cashmere that has already been worn and washed shows you exactly how it ages — no guesswork about pilling. Check the cuffs, underarms and elbows, and pass on anything thin or moth-marked.
Two. Independent designers and craft workshops. Small knitwear makers who name their spinner and their workshop give you the transparency the grading labels promise and rarely deliver.
Three. Accessible luxury. The tier where a well-made, plain 100% cashmere jumper is priced for the making rather than the name. Run the checks; the good ones pass them.
Four. Selective mainstream luxury. Worth it for a piece you will wear for a decade from a house whose knitwear is its core craft, not a seasonal add-on.
Skip the mid-tier mass market. That is where “cashmere” is most often a blend sold on the strength of the word, or short-fibre yarn that looks good on the hanger and pills by Christmas.
Frequently asked questions
What is the best grade of cashmere?
Retailers usually call the finest and longest fibre “Grade A”, around 14 to 15.5 microns on Robert Old & Co’s scale. But there is no official grading system, so the term is a seller’s claim rather than a standard. The legal requirement in the US is an average of no more than 19 microns.
How many microns is good cashmere?
Below 16 microns is generally treated as premium by sellers such as GOBI Cashmere. Anything averaging over 19 microns does not meet the US labelling definition or the CCMI definition of cashmere.
Why does my cashmere jumper pill?
Pilling happens when short fibres work loose from the yarn and tangle on the surface. Shorter-fibre cashmere pills more, which is why every grading scheme links fibre length to durability. Some light pilling at friction points is normal; heavy pilling after a few wears points to short fibre.
Is Mongolian cashmere the best?
Mongolia and Inner Mongolia are widely described by sellers, including Robert Old & Co and GOBI Cashmere, as producing the finest fibre because of their harsh winters. But origin alone does not guarantee quality: how the fibre was sorted, dehaired, spun and knitted matters as much as where the goat lived.
Is a cashmere blend worth buying?
It can be, if it is priced as a blend and you know what you are getting. Cashmere mixed with wool or silk can be durable and practical. The problem is a blend priced, marketed or labelled as if it were pure cashmere.
How can I tell if cashmere is real?
You cannot be certain without laboratory testing, which is what the CCMI’s IWTO method is for. In the shop, read the label, check for prickle against the inside of your wrist, look for heavy pilling on display samples, and buy from sellers who name where and how the garment was made.
The honest takeaway
Cashmere is one of the few clothing words with a legal definition, and the definition is simpler than the marketing: fine goat down averaging 19 microns or less. The grades layered on top are a seller’s vocabulary. What you can verify — the label, the pilling, the recovery, the prickle and the maker’s willingness to name the supply chain — is a better guide to a jumper you will still wear in ten winters than any letter on a tag.
The next move is yours.
Sources: 16 CFR § 300.19, use of the term “cashmere” · Cashmere and Camel Hair Manufacturers Institute, definitions · Wini Labrecque, cashmere, mohair and wool fibre basics (Cornell-hosted) · Robert Old & Co, cashmere grades · GOBI Cashmere, micron guide
