The question is usually framed as whether cashmere is worth the money, which already assumes the answer is a matter of budget. It is not. The two fibres behave differently, fail differently and belong in different parts of a wardrobe, and the better question is which one belongs in the garment you are about to buy.

What follows is a straight comparison on the five things that actually decide it: warmth for weight, durability, pilling, cost over time, and how each one feels after three years rather than three days.

The two fibres, side by side

Wool comes from sheep. Cashmere comes from the undercoat of a goat, and only the undercoat, which is the fine insulating layer beneath a coarse outer coat. That distinction explains almost everything that follows.

Because it is an undercoat, cashmere is extremely fine. A typical cashmere fibre measures between 14 and 19 microns, which puts it below all but the finest merino. Fineness is why it feels the way it does: the fibre bends against skin rather than pressing into it, so there is no prickle at all, even at the neck.

It is also scarce. A goat yields a few hundred grams of usable down a year against several kilograms of fleece from a sheep, and the fibre has to be separated from the coarse guard hairs by hand or machine before it can be spun. That scarcity, not any marketing decision, is most of the price difference.

The other structural difference matters more than the price. Cashmere fibres have fewer and shallower surface scales than wool, and much less crimp. Fewer scales means a smoother, softer surface. Less crimp means less natural elasticity, which is why cashmere drapes where wool springs. The full picture on the wool side, including what the labels mean, is in wool explained.

Warmth for weight

Cashmere wins this one, and it is not close. For the same weight of cloth, cashmere insulates substantially better than wool, because the fibres are finer and therefore more of them are packed into the same mass, trapping more air.

In practice this means a cashmere jumper of a given warmth is noticeably lighter and thinner than its wool equivalent. That is the real luxury of the fibre, more than softness: warmth without bulk, which is what makes it work under a jacket where a thick wool would not fit.

Wool answers in a different register. It handles moisture far better, absorbing a third of its weight in vapour before feeling damp and continuing to insulate when genuinely wet. Cashmere absorbs less and loses more of its insulating value once saturated. For a dry cold, cashmere. For a wet one, wool.

There is a comfort difference too. Wool regulates temperature across a wider band, which is why a wool layer is comfortable walking outside and sitting in a warm room. Cashmere is warmer but less adaptable, and in a heated office it can tip into too warm quite quickly.

Blends complicate the picture usefully. A wool and cashmere blend, commonly around seventy to thirty, keeps most of the softness while borrowing the strength and spring of wool. For a jumper that has to be worn often and still feel good against skin, a blend frequently beats either fibre alone, and it costs considerably less than pure cashmere.

Durability and pilling

Wool wins this one, and it is also not close. The same fineness that makes cashmere soft makes it weak, and the same lack of crimp that makes it drape means it recovers less well from stretching.

Pilling is where this shows first. A pill forms when short fibre ends work loose from the yarn and tangle, and cashmere has both shorter fibres and a smoother surface that lets them migrate. All cashmere pills in the first weeks. Good cashmere, made from long fibres and tightly spun, stops after that initial shedding settles. Poor cashmere pills indefinitely, because it is full of short fibre that keeps working free.

That first round of pilling is not a defect and should be removed with a comb rather than a razor, which cuts the surface and creates new short ends. After two or three combings a good cashmere garment usually settles and stays settled.

Wool pills too, but less, and sturdier wools barely at all. A lambswool or virgin wool Jumper TS006 will survive daily wear in a way that cashmere of the same price will not, and it holds a shoulder and a cuff far longer because the fibre springs back rather than relaxing.

Both fibres share one vulnerability, which is moths. Larvae feed on the protein in animal fibre and they are drawn to traces of skin and food rather than to clean cloth, so both wool and cashmere must be stored clean. Cashmere suffers more visibly when it is damaged, because a hole in a fine knit spreads where a sturdy wool holds.

Cost per wear over five years

The honest comparison is not price but price divided by the number of wears before the garment stops looking good.

Cashmere costs several times what comparable wool does, and in a garment worn hard, it does not last several times as long. Worn daily, under a bag strap, against a desk, cashmere thins at the elbow and the point of contact within a few seasons. In that use, wool is the better value by a wide margin and it is not a close call.

The calculation reverses for garments worn gently and often. A cashmere scarf, worn over a coat rather than against abrasion, can last fifteen years and look better each one as the surface blooms. A cashmere jumper worn once a week over a shirt rather than against skin will outlive one worn as a daily layer by many years.

So the useful rule is not about budget at all. Buy cashmere for the garments that are worn lightly and buy wool for the ones that are worn hard, whatever the budget allows. A Cardigan CA001 that goes on and off all day is a wool decision. The scarf that sits over a coat is a cashmere one. The broader argument for buying this way is in dressing less, choosing better.

Where wool wins

Outer layers, in every case. Coats, structured jackets, anything that takes weather or friction. Wool holds shape, resists water and recovers, and those three properties are exactly what an outer layer is for.

Everyday knitwear, meaning anything worn more than once a week. A Jumper TS005 in wool will take five years of regular wear. The same garment in cashmere will take two and will look tired for the last one.

Anything worn in wet weather, anything worn under a bag, anything travelled in. Wool creases less, recovers overnight on a hanger and tolerates being packed, which is why it remains the standard for clothes that have to work away from home.

And anything that needs structure. Cashmere has almost no body of its own, so a cashmere garment cut to hold a line will not hold it for long. If the shape is the point, the answer is wool.

There is a seasonal dimension too. Wool covers a longer stretch of the year, from early autumn through to spring, because it regulates across a wider temperature range. Cashmere earns its place in the coldest eight or ten weeks and in the thin layers worn indoors, which is a shorter window and worth factoring into what the garment costs per wear.

Where cashmere wins

Next to skin, always. Nothing else matches it for a garment worn against a bare neck, and for anyone who finds wool uncomfortable the difference is decisive rather than marginal.

Thin layers that have to be warm. A fine cashmere worn under a jacket gives warmth that a wool of the same thickness cannot, without the bulk that would spoil the fit of whatever goes over it.

Accessories, which is where cashmere is most clearly worth the money. A scarf or a shawl is worn gently, close to the face where softness is most noticeable, and lasts for decades. A Scarf Medium 01 is in the wardrobe long after the season it was bought for is forgotten.

And anything where drape is the point. Cashmere falls rather than stands, which suits a loose jumper, a shawl collar or a wide scarf, and makes it the wrong choice for anything tailored.

One more case for cashmere that gets overlooked: travel. A fine cashmere layer takes almost no space in a bag, emerges without creases and covers a wide range of indoor temperatures, which makes it one of the most efficient things that can be packed even though it is the most expensive per gram.

How to tell quality in a shop

Four tests, none of which requires a label. First, stretch a small section gently and release it. Good cashmere returns almost fully. Poor cashmere stays slightly stretched, which means short fibres and a garment that will bag at the elbows within a season.

Second, rub a section briskly between your palms for a few seconds. A small amount of surface fuzz is normal. A visible cloud of loose fibre means the yarn is full of short ends and the garment will pill without end.

Third, hold it to the light. A dense, even knit with no light showing through the stitches indicates a tightly spun yarn and a well made garment. Thin, loose knitting is where cost is usually cut, and it is where the garment will fail first.

Fourth, weigh it in the hand. Two cashmere jumpers of the same size can differ considerably in weight, and the heavier one almost always has more fibre in it. Ply is the same question asked differently: a two ply yarn is stronger and lasts longer than a single, and the difference is obvious when you compare them side by side.

Apply the same four tests to wool and the results are just as informative. Both fibres reward being judged by hand rather than by price, and both sit in the EVERYDAY collection doing different jobs.