That Yarn · Journal
Lambswool vs Merino: Which Is Warmer, Softer, and Better?
The short answer surprises most people: it's not really a contest. Merino and lambswool aren't rival choices — they describe two different things about a wool, and a single fiber can be both at once. Here's what that means for warmth, softness, and which to choose.
Of all the words that appear on a wool label, "merino" and "lambswool" are the two you meet most often. They turn up in yarn descriptions, on garment tags, side by side — usually presented as if you must pick between them. It is one of the most common framings in wool, and it rests on a quiet confusion, because the two words do not answer the same question.
Once you see what each actually describes, wool labels become legible and choosing yarn becomes far easier. Here is the distinction that clears it up.
They describe two different things
This is the crux, and everything else follows from it.
| Term | Answers the question | Determined by |
|---|---|---|
| Merino | Which breed of sheep? | Genetics — the Merino breed |
| Lambswool | Which shearing? | Age — the first shearing, any breed |
Merino names a breed of sheep, prized for growing exceptionally fine wool. A Merino sheep can be shorn throughout its life; its wool is Merino wool at any age.
Lambswool names the wool from a sheep's very first shearing, usually around six or seven months old — and it can come from any breed. It describes when the wool was harvested, not what animal grew it.
Which leads to the fact that dissolves the whole either/or framing:
Merino lambswool exists — the first shearing of a Merino lamb. It is softer than ordinary Merino and softer than ordinary lambswool, because it combines both qualities. "Merino or lambswool" is often a false choice. A fiber can be both.
So the real question is not which to pick, but what each word is telling you about the wool in your hands. One speaks to fineness; the other speaks to softness and structure. They are different axes.
What Merino tells you: fineness
Because Merino sheep are bred for fine fleece, the word signals a low micron count — the diameter of the fiber, and the main driver of how a wool behaves against the skin.
| Merino grade | Approximate microns |
|---|---|
| Ultrafine | ≈ 15–17.5 µm |
| Superfine | ≈ 17.6–18.5 µm |
| Fine | ≈ 18.6–20 µm |
| Medium / broad | ≈ 20–24 µm |
Merino also tends to have a long staple and a high, regular crimp, which give it two further qualities: strong, even yarn that resists pilling, and real elastic memory — the springback that lets ribbing recover and a garment hold its shape. Our guide to what superfine wool really means works through the grades and where "superfine" actually sits.
The trade is delicacy. Fine Merino is more prone to pilling under friction and prefers gentle washing. Fineness and durability pull in opposite directions.
What lambswool tells you: softness and taper
Lambswool's softness comes from a different place, and it is a place the fineness number does not capture.
Because the wool has never been shorn before, each fiber still has its original, naturally tapered tip — a fine, rounded end rather than the blunt cut end of wool from a previously shorn adult. Those soft tips are gentler against skin, and they are the real reason lambswool feels the way it does.
This is why lambswool can feel soft even when its micron count is not especially low. Softness is not only about diameter; it is about the tip, the crimp, and the newness of the fiber. The average is not the whole story.
Because lambswool can come from any breed, its fineness varies widely — often averaging around 25 microns, higher than fine Merino. It also has a shorter staple, since it comes from a single early shearing, which makes for a lofty, springy, slightly less durable yarn. What lambswool reliably offers is that first-shearing softness and a natural, airy bounce.
Putting the two axes together
Now the comparison makes sense, because the two words are measuring different things.
| Quality | Merino (breed) | Lambswool (first shearing) |
|---|---|---|
| Defined by | Genetics | Age at shearing |
| Typical fineness | Very fine (≈ 15–24 µm) | Variable (≈ 22–28 µm) |
| Source of softness | Low micron diameter | Tapered, unshorn fiber tips |
| Staple length | Long | Short |
| Elastic memory | High | Moderate; lofty |
| Pilling resistance | Good (long staple) | Lower (short staple) |
| Signature quality | Smooth, sleek, next-to-skin | Soft, airy, springy loft |
Read across the "source of softness" row and the whole point of the article is there: Merino is soft because it is thin; lambswool is soft because it is young. Two different routes to the same virtue.
Reading a label
Once you hold the two axes apart, wool labels become legible.
- "Merino" — a fine fiber from the Merino breed, of any age. Tells you about fineness, not shearing.
- "Lambswool" — first-shearing wool of an unstated breed. Tells you about softness and youth, not fineness. Breed unknown, so fineness varies.
- "Merino lambswool" — the best of both: fine and first-shearing. The softest, and usually the most expensive.
- "Pure new wool" / "virgin wool" — first-use wool, not recycled. A quality marker, but silent on breed and age.
When a cone is a mill-end without full documentation, the fineness may simply be unstated. In that case the honest approach is to judge by hand and swatch rather than to assume a micron figure — the same principle we apply to any partially labelled surplus.
When to reach for each
Because they are different axes, this is less "either/or" than "what does the project want most."
| Reach for Merino when you want… | Reach for lambswool when you want… |
|---|---|
| Next-to-skin smoothness with no prickle | Cosy, lofty warmth with a soft hand |
| Fine-gauge, drapey, lightweight knits | Body, bounce, and structure in a fabric |
| Strong shape memory and crisp ribbing | An airy, insulating, casual sweater |
| Base layers, fine sweaters, next-to-skin wear | Autumn and winter knits, blankets, accessories |
And when you want both at once — next-to-skin softness with first-shearing tenderness — Merino lambswool is the answer the false-choice framing hides.
On the cone
Both fibers reach makers as cone yarn, frequently as surplus from luxury knitwear production. On the cone they behave as all industrial yarn does: firm, sometimes carrying spinning oil, and quiet about their true softness until washed. Both bloom — Merino into a smooth, defined fabric, lambswool into a lofty, gently haloed one.
As always, the roughness on arrival is packaging, not character, and a swatch washed before you judge it will tell you what the finished piece will be. Our guide to blooming covers what to expect.
The difference, in one line
Merino tells you the breed; lambswool tells you the shearing. One is about fineness, the other about first-shearing softness, and the finest wool of all — Merino lambswool — is both. The next time a label offers you a choice between them, you will know it is often not a choice at all.
Frequently asked questions
What is the difference between lambswool and merino wool?
They describe different things, which is why comparing them directly is a little misleading. Merino is a breed of sheep known for very fine wool, shearable at any age. Lambswool is wool from any breed's first shearing, around six or seven months old. Merino is about fineness; lambswool is about first-shearing softness. They aren't mutually exclusive — Merino lambswool exists and is the softest of all.
Is lambswool warmer than merino?
Lambswool often feels a little warmer and cosier, because its shorter, lofty, springy fibers trap more air. But neither is simply "warmer" by rule — warmth comes from how much still air a yarn traps, which depends on fineness and especially on how the yarn is spun, not on the label. A lofty lambswool and a lofty merino can be equally warm; merino is also prized for regulating temperature across seasons.
Is lambswool softer than merino?
It depends on the specific wool. Merino is usually finer, and fineness is the main driver of softness, so a fine merino often feels softer. But lambswool has its own softness from the naturally tapered, never-before-shorn tips of the fiber, so it can feel soft even at a higher micron count. They reach softness by different routes — and Merino lambswool, which is both, is the softest of all.
Which is better, lambswool or merino?
Neither is better overall — they suit different things, and the "better" one depends on your project. Merino's fineness makes it ideal for smooth, next-to-skin garments with good shape memory and less pilling. Lambswool's loft makes it wonderful for cosy, textured, warm pieces with body. And because a wool can be both, the real question is fineness, softness, and loft — not the label alone.
Is lambswool good for winter?
Yes — lambswool is an excellent winter fiber. Its short, springy, lofty fibers trap a lot of insulating air, giving it a warm, cosy character well suited to sweaters, hats, and scarves. For next-to-skin winter layers you may prefer a fine merino or Merino lambswool for softness, but for warmth and body, lambswool is a classic winter choice.
Is lambswool soft?
Yes. Lambswool comes from a sheep's very first shearing, so its fiber tips are naturally tapered and have never been cut, which gives it a distinctive gentle softness. It's softer than most regular wool of the same breed. The very softest wool of all is Merino lambswool, which combines this first-shearing softness with Merino's fineness.
What is lambswool?
Lambswool is wool taken from a sheep's first shearing, usually around six or seven months of age. Because the fibers have never been cut before, their tips are naturally tapered, giving lambswool a soft, springy, lofty character. It can come from any breed — "lambswool" describes the shearing, not the sheep — so a Merino lamb's first shearing is called Merino lambswool.
Can wool be both merino and lambswool?
Yes, and this is the key to the whole comparison. Merino lambswool is the first shearing of a Merino lamb. It combines Merino's fineness with lambswool's tapered, unshorn softness, making it softer than either alone — and usually the most expensive. This is why "lambswool vs merino" is often a false choice: a single fiber can be both.
How does lambswool compare to cashmere?
Cashmere is finer and softer than most lambswool, and warmer for its weight, which is why it's more expensive. Lambswool is springier, more elastic, and more hard-wearing. In a rough order of fineness and price, it runs lambswool, then fine merino, then cashmere — though a superfine Merino lambswool narrows the gap considerably. Each has its place.
Which should I choose for a sweater?
For a fine, sleek, next-to-skin sweater with good shape memory, choose merino. For a cosy, lofty, casual sweater with body and warmth, choose lambswool. For the softest of both worlds, look for Merino lambswool. And remember that how the yarn is spun and finished matters as much as the fiber name — a washed swatch tells you more than any label.
Some yarns don't come back.
That Yarn drops new mill-end on the 1st and 15th.
Have a question about a specific cone? Write to us at hello@thatyarn.com — we answer every email.
