Our guide to yarn fibres
One of the most exciting things about knitting and crochet is discovering the huge variety of yarns available. Walk into any yarn shop and you’ll find wool, cotton, alpaca, bamboo, linen, cashmere and countless blends, all with their own unique qualities.
But if you’re new to fibre types, it can be difficult to know what any of those labels actually mean. Why is one yarn perfect for a cosy winter jumper while another is better suited to a lightweight summer top? Why do some fibres feel soft and fluffy while others feel crisp and cool?
Understanding fibre properties can help you choose the right yarn for your project and avoid disappointment later. The same pattern worked in different fibres can look, feel and behave completely differently.
This guide explains some of the most common yarn fibres you’ll come across, their strengths and weaknesses, and the types of projects they’re best suited to.
Understanding fibre properties
Before we look at individual fibres, it helps to understand a few terms you’ll often hear makers use.
Warmth: Some fibres trap heat very effectively, making them ideal for winter garments and accessories. Others are breathable and help keep you cool.
Drape: Drape describes how a finished fabric hangs. A yarn with good drape will flow and move easily, while a yarn with less drape creates a more structured fabric.
Elasticity: Elastic fibres stretch and spring back into shape. This helps garments keep their fit over time and can make yarn easier to work with.
Stitch definition: Stitch definition refers to how clearly individual stitches can be seen in the finished fabric. Good stitch definition is particularly useful for textured knitting, cables, lace and detailed crochet stitch patterns.
Halo: A halo is the soft, fuzzy cloud of fibres that sits around some yarns, particularly mohair and alpaca. It creates a cosy appearance but can make intricate stitch patterns less visible.
Wool
Wool is often the fibre people think of first when they imagine yarn. It comes from sheep and has been used for thousands of years.
Properties
- Warm and insulating
- Naturally elastic
- Breathable
- Good stitch definition
- Can absorb moisture without feeling damp
- Can feel itchy for some people
Best for
- Jumpers and cardigans
- Hats and mittens
- Scarves and cowls
- Blankets
- Accessories
Good to know: Wool is one of the most beginner-friendly fibres because its elasticity makes it forgiving to work with. It also tends to hold its shape well in both knitted and crocheted projects.
Merino Wool
Merino wool comes from Merino sheep and is one of the most popular fibres for both knitting and crochet.
Properties
- Exceptionally soft
- Fine fibres that feel comfortable against the skin
- Warm but lightweight
- Excellent elasticity
- Smooth stitch definition
Best for
- Baby garments
- Shawls
- Socks
- Jumpers and cardigans
- Crochet garments and accessories
Good to know: Merino is often recommended for projects worn directly against the skin because of its softness. It also showcases textured stitches beautifully.
Cashmere
Cashmere comes from cashmere goats and is considered one of the world’s luxury fibres.
Properties
- Extremely soft
- Lightweight
- Very warm for its weight
- Beautiful drape
- Delicate compared to wool
Best for
- Luxury scarves
- Shawls
- Special garments
- Lightweight accessories
Good to know: Cashmere is often blended with other fibres to improve durability while retaining its luxurious softness.
Silk
Silk is a natural fibre produced by silkworms and is prized for its smooth texture, beautiful sheen and luxurious feel.
Properties
- Soft and smooth
- Excellent drape
- Naturally lustrous
- Strong for its weight
- Lightweight but insulating
- Little elasticity
Best for
- Shawls
- Lightweight garments
- Lace projects
- Luxury accessories
- Blended yarns
Good to know: Silk creates fabrics with beautiful drape and a subtle sheen. It is often blended with fibres such as merino or alpaca to add softness and shine while improving elasticity.
Mohair
Mohair comes from Angora goats and is famous for its distinctive fluffy appearance.
Properties
- Light yet warm
- Creates a soft halo
- Strong fibre
- Excellent warmth-to-weight ratio
- Adds softness and texture
- Can feel itchy to some people
Best for
- Fluffy jumpers
- Shawls
- Lightweight garments
- Statement accessories
Good to know: Mohair is often held alongside another yarn in knitting or crochet to add softness, warmth and a beautiful halo effect.
Alpaca
Alpaca fibre comes from... you guessed it... alpacas, and is prized for its softness and warmth.
Properties
- Very warm
- Soft and silky
- Excellent drape
- Less elastic than wool
- Lightweight
Best for
- Shawls
- Scarves
- Winter garments
- Cosy accessories
Good to know: Because alpaca has less elasticity than sheep’s wool, garments can stretch slightly over time. This is worth considering when choosing patterns for both knitting and crochet.
Yak
Yak fibre comes from the soft undercoat of yaks who live in high-altitude regions.
Properties
- Exceptionally warm
- Soft and smooth
- Lightweight
- Excellent insulation
- Often naturally dark in colour
Best for
- Luxury accessories
- Hats and cowls
- Winter garments
- Blended yarns
Good to know: Yak is commonly blended with merino or cashmere to combine warmth, softness and durability.
Cotton
Cotton is one of the most widely used plant fibres in the world and is especially popular for crochet projects.
Properties
- Cool and breathable
- Strong and durable
- Excellent stitch definition
- Smooth texture
- Little elasticity
Best for
- Summer garments
- Baby items
- Homeware
- Amigurumi
- Dishcloths and washcloths
- Bags and market totes
Good to know: Cotton’s lack of stretch means it can feel less forgiving than wool, but it excels when you want crisp stitch definition and durable finished projects. This is one reason it is a favourite among crocheters.
Mercerised Cotton
Mercerised cotton is cotton that has been specially treated to improve its appearance and performance.
Properties
- Smooth and silky
- Increased strength
- Enhanced stitch definition
- Beautiful sheen
- Vibrant colours
Best for
- Crochet lace
- Decorative projects
- Summer garments
- Home décor
- Market bags
Good to know: Mercerised cotton is particularly popular for crochet because it produces crisp, well-defined stitches with a polished finish.
Linen
Linen is made from the flax plant and has been used in textiles for centuries.
Properties
- Cool and breathable
- Strong and durable
- Excellent drape
- Becomes softer over time
- Naturally textured appearance
Best for
- Summer tops
- Lightweight garments
- Shawls
- Cardigans
- Warm-weather accessories
Good to know: Linen often feels quite crisp when you’re working with it but softens significantly after washing and wear.
Bamboo
Bamboo yarn is valued for its softness and beautiful drape.
Properties
- Soft and silky
- Excellent drape
- Cool against the skin
- Moisture-wicking
- Gentle sheen
Best for
- Summer garments
- Shawls
- Lightweight accessories
- Baby items
Good to know: Bamboo creates flowing fabrics in both knitting and crochet. It is often blended with wool or cotton to add structure and improve elasticity.
Which fibre should beginners choose?
If you’re just starting out with knitting or crochet, wool and merino wool are excellent choices. Their elasticity makes them easier to work with and more forgiving of tension variations.
For crochet, cotton is also a popular beginner fibre because of its durability and excellent stitch definition, especially for toys, homeware and accessories.
As your confidence grows, exploring fibres like alpaca, linen, mohair and yak can help you discover new textures, drape and warmth.
The best fibre is ultimately the one that suits your project, your budget and what you enjoy working with. Every fibre has its own personality, and finding your favourites is part of the fun.