Cashmere: what grade actually means

Cashmere costs anywhere from $60 to $2,000, and the label rarely explains why. Most of the difference comes down to two properties of the fiber: how fine it is and how long it is. Everything else follows from those two.

Where it comes from

Cashmere is the soft undercoat of cashmere goats, which live mostly on the high, cold plateaus of Mongolia and Inner Mongolia. Each spring the goats shed, and herders comb out the down by hand. One goat yields only a few ounces of usable fiber a year. That scarcity is the first reason cashmere is expensive. The second is everything that happens after the combing.

Fineness: the micron count

Fineness is measured in microns, the diameter of a single fiber. In the U.S., a fabric must average 19 microns or finer to be labeled cashmere at all. The very best cashmere is closer to 14 or 15 microns. Finer fiber feels softer against the skin, drapes more fluidly, and is warmer for its weight.

Length: the part no one mentions

Fiber length matters just as much. Long fibers, around 34–36 mm and up, can be spun into smooth, strong yarn with few loose ends. Short fibers leave more ends poking out of the yarn, and those ends work loose and ball up. That's pilling. A sweater that pills badly after one season was almost certainly made from short fiber, no matter how soft it felt in the store.

So what is "Grade A"?

"Grade A," "Grade B," and "Grade C" are trade shorthand, not a regulated standard. Broadly:

• Grade A: the finest and longest fibers, roughly 14–15.5 microns and long staple. Soft, durable, and rare.
• Grade B: somewhat coarser, around 16–19 microns. Pleasant, but with less longevity.
• Grade C: coarse fiber, often around 30 microns. It shouldn't really be called cashmere.

Because the grades aren't policed, treat "Grade A" as a claim worth backing up. Brands that are serious about it will usually tell you more: where the fiber is sourced, the micron range, and who spins and knits it.

Ply and gauge

Ply is how many strands are twisted together to make the yarn. Two-ply is the standard for good knitwear because it's balanced, durable, and resists twisting. Single-ply is light but wears quickly. Gauge is how many stitches fit in an inch, so a lower gauge means a chunkier knit. Neither is a direct measure of quality. A 2-ply, 12-gauge sweater made from short fiber will still pill.

How to tell in person

• Stretch a cuff and let go. Good cashmere springs back.
• Rub the surface with your palm for a few seconds. A cloud of fuzz suggests short fiber.
• Look at the knit. It should be even and dense, not loose and airy, which is a common way to stretch less fiber further.
• Be skeptical of extreme softness in a cheap sweater. Heavy washing and softeners can make poor fiber feel lovely for exactly one season.

Care, briefly

Hand wash in cool water with a gentle wool wash, press out the water in a towel, and dry it flat. Fold it, never hang it. Remove the occasional pill with a cashmere comb. Treated well, good cashmere gets softer for years.