Grading Cashmere Sweaters: Micron and Staple Length Beat the Label

November 5, 2026

Cashmere quality rests on two measurable specs: fiber diameter in microns and staple length in millimeters. Fine, long fiber at roughly 14 to 16 microns and 35 millimeters or more pills slowly and stays soft. The word cashmere on a label, and even grade claims, are unregulated, so the specs and the hand tests matter more than the branding.

The numbers that decide the grade

Fiber diameter is measured in microns. The Cashmere and Camel Hair Manufacturers Institute sets the ceiling for calling a fiber cashmere at an average under 19 microns. The trade's top tier, usually called Grade A, sits around 14 to 16 microns, with Grade B coarser at roughly 18 to 19 and Grade C at or beyond the ceiling, sometimes far beyond.

Staple length is the second number and the one shoppers ignore. Long staple fiber, 35 millimeters and up, twists into yarn with more overlap, so the yarn holds together under friction. Short staple yarn feels soft on day one and then sheds its short ends as pills within a month. Softness is diameter. Durability is length. A good sweater needs both.

Why there is no grade police

No regulator certifies cashmere grades before a sweater reaches a shelf. Grade A is a trade convention, consistent across serious mills but voluntary. That is why two sweaters with identical label language can be five years apart in lifespan, and why the mill behind the yarn, firms like Todd and Duncan that publish their fiber specs, is a more reliable signal than any grade word on a hangtag.

Ask the two questions directly: what micron, what staple length. A seller who knows both numbers is selling fiber. A seller who answers with adjectives is selling a story, and the story is usually wrapped around short staple fiber bought cheap.

In store tests that actually discriminate

Stretch a small area gently and let go: a tight, even knit recovers its shape, a loose knit stays bagged, and loose knits pill faster because the yarns move against each other. Hold the sweater to the light: a halo of long fuzzy fibers sticking out all over signals short staple and early pilling; a clean surface with a soft sheen is the long fiber look.

Rub the same spot twenty times with your palm. Good cashmere warms and stays smooth. A sweater that is already raising pills in the store, under the gentlest friction it will ever meet, is telling you its staple length without a lab report.

Grading this fall's price tiers

Budget cashmere under a hundred dollars is almost always short staple: pleasant for a season, honest if priced as such, a poor deal if marketed as heirloom. Mid tier sweaters live or die on whether the brand publishes specs; the ones that do, at 15 to 16 microns with long staple, are this fall's best value. Luxury pricing buys finer fiber, tighter knitting, and better finishing, with diminishing returns past the point where the specs stop improving.

The grade that matters is the one you can verify. Buy the sweater whose numbers you were told, from the seller who told them without being asked twice.

Keep reading: Quick answers, About Trend Grade HQ, and Grading Wool Coats for Fall 2026: Weight and Lining Beat the Label cover the nearby cases in this series.

Frequently asked questions

What micron count should I look for in a cashmere sweater?

Around 14 to 16 microns is the fine end of the trade range and gives the softest hand. Anything averaging above 19 microns falls outside the institute definition of cashmere altogether, whatever the label calls the blend. Ask for the number; reputable sellers know it.

Why does cheap cashmere pill so fast?

Short staple fibers. Their ends work out of the yarn under friction and tangle into pills. Long staple fiber at 35 millimeters or more stays locked in the yarn, which is why two sweaters of the same weight and price class can age completely differently.

Is more ply always better in cashmere?

No. Ply counts yarns twisted together, and a tightly knitted two ply of long staple fiber will outlast a loose four ply of short staple. Ply tells you about weight and warmth. It says nothing about fiber quality on its own.

Can I test cashmere quality without a label spec?

Partly. The stretch recovery test, the light test for surface fuzz, and twenty palm rubs in one spot will sort a rack into likely long staple and likely short staple piles. They cannot give you microns, but they catch the worst offenders reliably.