Alpaca vs Cashmere: Which Is Warmer, and Which Is Softer?

Search this comparison and you will find the case argued almost entirely by people selling alpaca, usually with the same two claims: that alpaca is warmer because the strands are hollow, and that it rivals cashmere for softness at a fraction of the price. Neither claim survives contact with the research intact. The second depends entirely on which alpaca you are holding.

Here is what the measured evidence supports on fineness, warmth, durability and prickle, where it runs out, and how to choose between the two fibres for a British winter.

Quick Answer

Cashmere is finer than alpaca and therefore softer on average: cashmere runs roughly 13 to 19 microns with a legal ceiling of 19 microns on the mean, while alpaca spans about 15 to 36 microns across the whole clip, with only the finest grades overlapping cashmere's range. On warmth, no acceptable source gives a measured result showing alpaca beats cashmere, and the usual explanation for it is wrong, because alpaca is not hollow. A proportion of the fibres carry a medulla, an air filled or fragmented core, and medullation rises with fibre diameter and with the age of the animal. Fabric weight, knit density and garment construction determine warmth far more than the choice between these two fibres.

Softness: the Micron Question

Softness in a knitted garment comes mainly from fibre diameter, because a finer filament bends more readily when it presses against skin instead of resisting and registering as prickle.

Cashmere holds the tighter range, and it has a legal ceiling. Under the definition used by the Cashmere and Camel Hair Manufacturers Institute and the US Wool Products Labeling Act, cashmere must have a mean diameter of 19 microns or less, a coefficient of variation of 24% or less around that mean, and no more than 3% by weight of fibres coarser than 30 microns. McGregor's review for Australia's Rural Industries Research and Development Corporation gives a typical working range of 13 to 19 microns.

Alpaca has no such ceiling and a much wider spread. The Alpaca Owners Association puts the overall range at 15 to 36 microns, and McGregor's review gives 17 to 45 microns across everything the animal produces. The top of the alpaca range therefore overlaps cashmere; the bulk of the clip does not.

That is the honest comparison: at the fine end of the alpaca range the two fibres sit close together, and across the average of what each animal produces, cashmere comes out finer. A cheap alpaca jumper and a cheap cashmere jumper are not competing on equal terms, because "alpaca" on a label covers a far broader band of material than "cashmere" does.

Warmth: Where the Popular Claim Falls Down

The account you will meet everywhere says the fibre is hollow, trapping air like a thermos. The research does not support it as usually stated.

Alpaca is not a hollow fibre. Some strands carry a medulla, a core that may be air filled or fragmented, and the proportion varies a great deal between animals, colours and ages. A fibre with a discontinuous medulla is not a tube; it is a solid filament with intermittent pockets, which is a rather different thing from the sales description.

There is also counter evidence on whether medullation helps at all. Moore, Blache and Maloney, studying fibre diameter and insulation in alpacas in Small Ruminant Research, found finer fibres gave no thermal advantage in still air and increased heat loss above 4 metres per second of wind. The Alpaca Owners Association's own commissioned review of fibre claims flags the microscopic air pockets giving high insulation values assertion as needing more validation.

What the Medulla Research Actually Found

Kuźnicka and colleagues, publishing in Archives Animal Breeding in 2024, measured medullation directly. They found 63.97% of fibres medullated in white alpaca and 73.52% in coloured, with 45.39% in animals up to a year old against 86.91% in those over four. They identified three types, non medullated, discontinuously medullated and continuously medullated, with the discontinuous form predominating, and reported a higher proportion of non medullated fibres in the thinner wools.

Their own comment on insulation is tentative: alpaca is characterised by good thermal insulation, which may be due to the medulla. That is a careful sentence, and it is a long way from the certainty with which the hollow fibre claim usually arrives.

Note the irony buried in the data. The softest alpaca, the sort sold at a premium, is the least medullated, because medullation tracks fibre diameter and animal age. If the medulla were doing the insulating work, the finest alpaca would be the least warm, which is the opposite of what the marketing claims.

What Really Decides Warmth in a Jumper

So what does decide it? How much still air the fabric holds, which comes down to fabric weight, gauge, knit structure and fit.

A heavyweight cable knit in either fibre will beat a fine gauge jumper in the other every time, because the cable adds surface and depth and the heavier fabric holds more air. Fit matters too: a jumper with room for a thin layer of warm air next to the body outperforms a tight one in the same yarn.

Comparing the fibres without holding the garment constant is comparing nothing at all. If warmth is your priority, ask the brand for the fabric weight in grams per square metre and the weight category, and compare those instead of the fibre names.

Side by Side on the Evidence

Durability, Pilling and Drape

Alpaca staple tends to run longer than cashmere's 20 to 50 mm processed length, and staple length is the property that governs pilling. Li and Zhou's work on cashmere knitted fabric identified fibre length, particularly fibres under 7.5 mm, as responsible for the pilling rate, with yarn twist and fabric density making little difference across their test range. Longer alpaca therefore tends to hold together at the fabric surface better than fine cashmere does. Neither is immune: the International Wool Textile Organisation records that pilling occurs in all fibres through abrasion.

Drape is where alpaca announces itself. It has less crimp than sheep's wool and less spring than merino, so an alpaca jumper hangs rather than holds, and a heavy one can grow across the shoulders over time. That makes the fibre excellent for a scarf or a wrap, where fluid drape is the point, and demanding in a jumper, where construction has to do the work the fibre will not.

Cashmere has the same shortcoming for a different reason, which is why both fibres benefit from being blended with merino when a garment needs to keep its line.

Storage matters for both, because moths are drawn to protein fibres and to the traces of skin and food left on a worn garment. Wash or air a piece before putting it away for the summer, store it folded rather than hung so the shoulders keep their shape, and keep it somewhere dry and dark. Follow the care label on your own garment, since blends and finishes vary.

Itch, Lanolin and Sensitive Skin

Prickle is a mechanical effect rather than an allergic one. Coarse fibre ends resist when they press against skin, and above roughly 30 microns most people feel it as itch, which is why the micron ranges above matter for comfort as well as for softness.

On skin feel, the Alpaca Owners Association notes that alpaca is free of lanolin and has a lower angled scale structure, which reduces the prickle sometimes met with sheep's wool. That is a reasonable statement about fibre structure, and it explains why an alpaca scarf can feel smoother than a wool one of similar fineness.

It is not a medical claim, and the association's own research review lists hypoallergenic among the assertions needing validation, so nobody should tell you alpaca will suit eczema or a diagnosed wool allergy. Anyone with a skin condition is better served by a patch test against the actual garment than by a fibre label.

Baby Alpaca and Royal Alpaca Are Trade Terms

Alpaca grades sound more official than cashmere's A, B and C, and in one country they partly are. The US Alpaca Fiber Standard sets numbered bands: Grade 0 at 15.0 to 16.9 microns, Grade 1 at 17.0 to 19.9, Grade 2 at 20.0 to 22.9, and so on up to Grade 6 at 32.0 to 34.9.

What the committee behind it declined to do was attach names. It found terms such as baby, royal baby, superfine and fine inconsistent across the world, and left them off the standard altogether. So "baby alpaca" on a swing tag is a description of intent rather than a defined threshold, and it does not mean the fibre came from a baby animal.

The same caution applies to cashmere's letter grades, which our guide to cashmere grades covers in full. In both cases the useful questions are the same: what is the micron figure, who measured it, and who spun the yarn?

Price, Yield and What You Get for It

The price gap between the two fibres comes down to yield. An alpaca produces several kilos of fleece a year, while a cashmere goat gives roughly 110 to 150 grams of combed down over the same period, and only about a quarter of that raw fleece is usable after dehairing. Several goats stand behind one cashmere jumper; one alpaca covers several garments.

That does not make alpaca the better buy by default. The finest alpaca grades are not cheap, and a well made alpaca garment can cost more than an indifferent cashmere one, because construction, gauge and country of make move the price as much as the fibre does. Sourcing matters too: Paul James takes the alpaca in its accessories from the Peruvian Andes and has the socks hand linked in Leicestershire, and that finishing is a real part of what the piece costs.

Choosing Between Them

• Softness against a bare neck: cashmere wins on the average of what each fibre offers, and only the finest alpaca closes the gap, at a price that makes the saving less obvious.

• A jumper worn hard every week: the longer alpaca staple resists pilling better, though the fibre's weight and lack of spring mean construction has to hold the shape.

• Warmth: stop comparing fibres and compare garments, asking for the fabric weight, the gauge and the knit structure, because those decide the answer.

• Shape retention over years: a merino cashmere blend beats either fibre alone, since 90% merino with 10% cashmere gives softness plus the crimp and recovery that keeps cuffs and elbows honest.

• Scarves, wraps and socks: both fibres are at their best where drape and softness matter and shape does not, which is why so much fine alpaca and cashmere is sold as accessories.

Paul James knits cashmere and merino cashmere jumpers in Leicester and uses alpaca in accessories rather than in knitwear. The alpaca yarn guide sets out what the brand does with it, which is a narrower answer than an alpaca specialist would give you and an honest one.

Frequently Asked Questions

Is alpaca warmer than cashmere?

No acceptable source gives a measured comparison showing that it is, so the claim should be treated as unproven. The explanation usually given, that the fibre is hollow, is not accurate: research published in Archives Animal Breeding in 2024 found roughly 64% to 74% of the strands are medullated rather than hollow, and the authors describe the insulation link only as possible. Warmth in a finished jumper is governed by fabric weight, gauge and knit structure far more than by which of the two animals grew the fibre.

Which is less itchy, alpaca or cashmere?

Prickle comes from coarse fibres resisting when they press against skin, so it tracks fibre diameter. Cashmere is capped at a 19 micron mean under the Cashmere and Camel Hair Manufacturers Institute definition and typically runs 13 to 19, while alpaca spans roughly 15 to 36 microns, so a random alpaca garment is more likely to prickle than a random cashmere one. Fine alpaca in the lowest grade bands sits within cashmere's range and feels comparable. Neither suits a diagnosed wool allergy.

Is alpaca cheaper than cashmere?

Standard grade alpaca generally costs less than cashmere, because an alpaca produces several kilos of fleece a year against roughly 110 to 150 grams of combed down from a cashmere goat, of which only about a quarter is usable. That yield gap sets the price gap. The finest alpaca grades are not cheap, and a good alpaca garment can cost more than an indifferent cashmere one, so price alone tells you little about fineness or how well the piece was knitted.

Does alpaca pill less than cashmere?

Directionally yes, because alpaca fibre is generally longer than cashmere's processed staple of roughly 20 to 50 mm, and length is what governs pilling. Li and Zhou found fibres under 7.5 mm were responsible for the pilling rate in cashmere knitted fabric, with twist and fabric density making little difference. Longer material holds in the yarn under abrasion. No animal fibre garment is pill free, and both benefit from a proper comb rather than a battery shaver.

Can alpaca and cashmere be blended together?

Yes, and blends of speciality fibres are common, usually with wool making up the majority. The reasoning is the same as for any blend: each fibre supplies what the others lack, with alpaca adding drape and length, cashmere adding fineness at the yarn surface, and merino supplying the crimp and elastic recovery that keeps a garment's shape. UK labelling rules require the percentage by weight of every constituent fibre in descending order, so the split is on the garment.

See the Range

Paul James knits cashmere and merino cashmere in its own Leicester factories, and the men's cashmere accessories are where the finest of those yarns ends up. For how the fibres sit alongside cotton, lambswool and British wool, the natural fibre guide covers the comparison. Questions about a particular garment are best put to the team directly.

Whichever fibre you choose, follow the care label on your own garment, since blends and finishes vary from piece to piece.