If I made a list of the fibres I’ve knit with the most over the last few years, merino would absolutely be at the top.

But right behind it?

Mohair and alpaca.

And honestly, younger me would be horrified.

My memories of both fibres in the 1980s were not great. Cheap alpaca from Peru that felt coarse and prickly. Mohair jumpers that looked like giant fluffy marshmallows and felt about as breathable as cling wrap.

But modern mohair and alpaca are very different.

And once you understand how they actually behave in fabric, you start understanding why knitters become obsessed with them.

Because both fibres create something that ordinary wool often can’t:

• warmth without massive weight
• softness
• drape
• movement
• elegance
• loft
• beautiful fabric texture

But they behave VERY differently.

And understanding those differences matters a lot when you're choosing yarns, substituting yarns, or trying to avoid spending weeks knitting a garment that turns into a stretched-out disaster after blocking.

If you'd like to browse while you read:

• Alpaca yarns: https://thewoolshop.co.nz/collections/alpaca
• Mohair yarns: https://thewoolshop.co.nz/collections/mohair-1
• Alpaca patterns: https://thewoolshop.co.nz/collections/alpaca-patterns
• Mohair patterns: https://thewoolshop.co.nz/collections/mohair-patterns

Why Knitters Compare Mohair and Alpaca

The reason people compare these fibres is simple.

Both are:

• soft
• warm
• lightweight
• luxurious
• drapey
• premium fibres

Both are often used in:

• Scandinavian knitting
• modern garment knitting
• oversized sweaters
• soft layering garments
• lightweight winter knits

And both can create those beautiful cloud-like fabrics everyone suddenly wants to wear.

But structurally?

They are very different beasts.

The Biggest Difference Between Mohair and Alpaca

The simplest way I can explain it is this:

Alpaca creates dense drape.

Mohair creates airy loft.

That difference changes EVERYTHING.

Alpaca: Dense, Liquid and Warm

Alpaca fibres are very smooth.

Unlike sheep wool, alpaca doesn’t have crimp. It doesn’t have the same scales gripping onto neighbouring fibres. The fibres are very straight and very slippery.

That’s why alpaca feels:

• liquid
• elegant
• slinky
• heavy-draping
• incredibly soft

It’s also why alpaca stretches.

A lot.

There’s no internal spring pulling the stitches back into shape.

So gravity wins.

When alpaca garments grow, they generally stretch:

• downward
• through the sleeves
• through the body length

Especially once blocked.

That’s why experienced knitters often:

• knit alpaca garments shorter
• size down
• tighten gauge slightly
• blend alpaca with another fibre for structure

And honestly? Once you understand this, a lot of alpaca behaviour suddenly makes sense.

Mohair: Airy, Floaty and Lofty

Mohair behaves differently.

Mohair fibres have flatter scales and a very open halo structure. The yarn blooms outward rather than draping heavily downward.

That’s why mohair feels:

• airy
• fluffy
• light
• floating
• soft-focus
• almost glowing in fabric

Instead of dense drape, mohair creates loft.

It traps air beautifully, which creates warmth without requiring a heavy garment.

That’s why so many modern knitting patterns use mohair.

Especially Scandinavian patterns.

You can create a sweater that looks chunky and warm without it weighing a tonne.

But mohair grows too.

Just differently.

Mohair tends to expand:

• outward
• downward
• across the fabric

Especially after wet blocking.

That’s why mohair garments can suddenly become much wider than expected if you don’t swatch properly.

Quick Comparison Table: Mohair vs Alpaca

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Why Both Fibres Stretch

This is one of the biggest things knitters misunderstand.

People often think:
“Oh no, the yarn stretched.”

But often it’s actually the fabric structure stretching.

Alpaca stretches because:

• it has no crimp
• it has no elasticity
• gravity pulls the stitches downward
• there’s no internal bounce-back

Mohair stretches because:

• the halo separates stitches
• the bloom expands
• the fabric opens up
• the structure spreads wider

Both fibres benefit massively from:

• proper swatching
• blocked swatching
• thoughtful gauge choices
• support fibres/blends

And honestly, if you skip swatching with either fibre, you’re gambling.

Mohair and Alpaca Feel Different To Wear

This is the bit that’s hard to explain until you’ve worn both.

Alpaca feels:

• cosy
• cocooning
• elegant
• warm
• smooth
• heavy in a comforting way

A good alpaca garment feels like being wrapped in warmth.

Mohair feels:

• airy
• soft-focus
• lightweight
• fluffy
• breathable
• cloud-like

A good mohair garment almost feels lighter than it should for the warmth it gives.

Neither is better.

They just solve different garment problems.

Why Some Alpaca Feels Scratchy

This surprises people.

Alpaca is technically hypoallergenic because it contains no lanolin, which is what many people react to in sheep wool.

But cheap alpaca can still feel prickly.

That’s usually because of fibre quality.

Baby alpaca and Suri alpaca use finer fibres from younger animals, which creates much softer yarns.

That’s why premium alpaca costs more.

It’s also why people who hated alpaca years ago are often shocked when they try modern baby alpaca blends.

Why Mohair Can Bother Sensitive People

Mohair is a bit different.

Even very soft kid mohair can irritate some people because of the floating halo fibres.

Sometimes it’s not true “itch.”

It’s:

• sensory irritation
• facial sensitivity
• respiratory sensitivity
• halo sensitivity

That’s why some knitters love mohair in:

• sweaters
• cardigans
• body garments

…but hate it:

• around the neck
• near the face
• in scarves

And honestly?
That’s completely valid.

You Don’t Have To Knit Pure Alpaca or Pure Mohair.

You do NOT have to go:
“full alpaca” or “full mohair.”

Most experienced knitters are constantly balancing:

• softness
• structure
• stretch
• cost
• drape
• warmth
• stitch definition

That’s where blends become brilliant.

For example:

• alpaca + merino gives softness with more structure
• mohair + sock yarn helps stabilise shape
• brushed alpaca creates warmth without huge density
• laceweight mohair softens rougher yarns beautifully
• blown constructions create warmth without heavy weight

Sometimes we’re not trying to make the fluffiest possible garment.

We’re trying to make the garment behave properly.

One Of My Favourite Tricks

One of my favourite things to do with chunky mohair yarns is hold them together with a sock yarn.

Especially a sock yarn with:

• merino
• nylon
• some structural memory

It doesn’t add much weight.

But it massively helps stabilise the fabric and stop the mohair from stretching too wide.

You still get:

• halo
• softness
• warmth
• loft

…but with much better shape retention.

And it’s often a much more economical way to knit too.

Mohair vs Alpaca for Different Projects

Alpaca is brilliant for:

• oversized winter sweaters
• cosy cardigans
• textured garments
• cables
• ribbing
• dense warm fabrics
• elegant drapey garments

Especially if you keep the gauge slightly denser.

Mohair is brilliant for:

• lightweight sweaters
• layering garments
• floaty fabrics
• oversized airy knits
• Scandinavian-style garments
• lightweight warmth
• halo softness

Especially when held together with another yarn.

Beginner Mistakes To Avoid

1. Not swatching properly

You MUST block your swatch.

Both fibres behave differently after blocking.

2. Thinking gauge is just about getting the right stitch count

With alpaca and mohair, you can technically “meet gauge” and still end up with a garment that behaves completely differently from the sample.

That’s because these fibres change:

• how the fabric hangs
• how heavy or airy it feels
• how much it stretches after blocking
• whether the stitches look open or dense
• how soft and fluid the garment becomes

Two swatches can technically hit the same stitch count and still create VERY different sweaters once worn.

That’s why blocked swatching matters so much with alpaca and mohair. You’re not just checking numbers. You’re checking the fabric itself.

3. Going too loose with alpaca

Loose alpaca can become dramatically longer over time.

4. Replacing mohair with standard yarn

Mohair changes fabric structure.

Replacing it changes the garment.

5. Buying by ball instead of metreage

Especially important with fluffy yarns.

6. Ignoring support fibres

Sometimes a small amount of:

• nylon
• merino
• acrylic
• silk

…is exactly what makes a garment successful long-term.

So Which One Should You Choose?

Honestly?

Neither fibre is “better.”

They just solve different problems.

If you want:

• airy softness
• lightweight warmth
• glowing halo
• floaty garments

…mohair is often the better choice.

If you want:

• elegant drape
• cocooning warmth
• dense softness
• luxurious winter garments

…alpaca is often incredible.

And often the best answer isn’t:
“choose one.”

It’s:
“learn how to combine them properly.”