heart03I’ve split the info on yarns into 3 sections. Click on the headings below to go straight to the information you need.

1. Yarn Types: This covers the different weights of yarns from superfine to super bulky as well as the novelty yarns such as tapes and eyelash yarn. There are also some tips on choosing yarns for new knitters.

2. Yarn Fibres: The different properties of various yarn fibres including details of what these fibres are like to knit with as well as the properties of the knitted fabric.

3. Yarn Substitution: Helpful hints on substituting yarns when you are following a pattern but don’t want to use the recommended yarn.

1. Yarn Types

Yarns are classified by their “yarn weight” which has nothing to do with how heavy they are but everything to do with the thickness of the yarn. The chart below is a quick reference guide to the different yarn weights and can help with yarn substitutions.

N.B. The terms two-ply, three-ply etc are misleading, in this context they are historical categories of yarn diameter and don’t necessarily have any relation to the number of strands or plies in the yarn.

The boundaries between the different traditional weight classes are not set in stone, different manufacturers may label yarn differently.

Never substitute a yarn based on the traditional name alone. Always check the recommended tension and knit a tension square to ensure you can match the tension of the pattern. See the section ‘ Substituting Yarns’ below.

Chart of Yarn Weights, Wraps per Inch, Yarn Names and Typical Tension / Gauge

Standard Weight Traditional Names
/ Yarn categories
Stitches per
over stocking stitch
Wraps per Inch
0 Lace Lace, Fingering,
33-40 23+
1 Superfine Sock, Fingering,
Baby, 2-ply, 3-ply
27-32 19-22
2 Fine Sport, Baby, 4-ply,
5-ply, light DK
23-26 15-18
3 Light DK, double knitting,
Light Worsted
21-24 12-14
4 Medium Worsted, Aran,
16-20 9-11
5 Bulky Chunky, Craft, Rug,
Heavy Worsted,
12-15 7-8
6 Super Bulky Super Chunky,
6-11 6 or less

Wraps per Inch: WPI

Wraps per inch or wpi is the number of strands of yarn that fit side by side in one inch. You can easily measure this by wrapping your yarn around a ruler without squashing it together but ensuring there are no gaps.

Beginners may be tempted to pick a pattern using a super bulky yarn so they’ll make quick progress. Sadly many find they are disappointed with garments made with super bulky yarn. Manipulating the large yarn and needles may also be awkward. It may be a better idea to pick a small project with a medium weight wool.

Novelty Yarns

Novelty yarns can be tricky for beginners to use and are perhaps best left until you are reasonably confident.

With some of the fluffy yarns it can sometimes be hard to see the stitch definition on your gauge swatch.

With shiny, slippery yarns it can be difficult to keep a consistent tension. (Try using wooden or bamboo needles and feeding the yarn in and out through your fingers or around your little finger to keep it under consistent tension.)

Ribbon yarns can sometimes get twisted up as you knit. Putting the ball of ribbon on a makeshift spindle or inside a narrow box can help ensure it unwinds without twisting.

Before starting a project with a novelty yarn it may be worth making a larger than usual swatch, this should give you time to iron out any problems.

If you’ve got novelty yarn you want to use up, try the Sirdar Loopa. You can make a boa in an evening and it’s great for showing off many novelty yarns to their best advantage.

2. Yarn Fibres

The comments below should give you a general idea of what to expect from the more common yarn fibres, there will always be exceptions and new yarn production methods are gradually ironing out many of the traditional problems associated with certain yarn fibres. It’s always worth doing an internet search on your chosen yarn before you buy, sites such as ravelry.com have yarn reviews, so hopefully you can avoid buying a yarn that has some hidden flaw.

Alpaca: This is a lovely fibre to work with but rather expensive. It is soft and has a slight sheen to it. It doesn’t contain lanolin so is often a good wool substitute for those allergic to wool. It’s a hollow fiber which helps regulate your temperature. Some alpaca yarns even claim to be water repellant and flame retardant, we plan to test this out in the Knitting Brain lab. It doesn’t felt as easily as wool, but hand washing is advised.

Angora: Angora comes from Angora rabbits. Angora yarn is very fluffy and tends to break quite easily and often sheds fibres like there’s no tomorrow. It is not very elastic so it is more often found blended with other fibres. Requires careful hand washing and will leave a trail of fluff until all the loosest fibres have been shed. Some of the more expensive hand spun angora yarns are easier to work with and don’t shed quite as much. May not be suitable for beginners but the finished fabric looks beautiful.

Bamboo: Most bamboo yarns are not made from bamboo fibre but of rayon, a semi-synthetic fiber derived from bamboo pulp. It is made from farmed bamboo, not the type that Pandas eat! Bamboo yarn is generally lightweight and breathable. It has a sheen to it and is a soft fibre. The down side is that many bamboo yarns need careful hand washing: it absorbs a lot of water and becomes more fragile when wet. Bamboo yarn is best knitted with blunter needles. The knitted fabric has a lovely drape to it making it ideal for plainer patterns where the yarn speaks for itself. The drape means it’s not best suited to cables or lace patterns.

Cashmere: This comes from the undercoat of the Pashim goat. Climate and diet affect the quality of the fleece, so there aren’t any European producers. Only about 100g of suitable fibre is produced per goat each year, hence why it remains an expensive luxury. Hand wash.

Cotton: Lovely and cool against the skin and some brands are super soft too. Cotton isn’t elastic so sweaters made from pure cotton can sag under their own weight, so a cotton blend is often a good compromise. Cotton is machine washable, hard wearing and often fairly cheap. Because it isn’t fluffy, cotton yarn is good at defining stitch patterns such as cables, on the down side uneven stitches tend to show up more.

Mercerised cotton has a lustre to it and is made up of many separate plies or threads. This can make it a bit harder for beginners to use because it’s easy to stab the needle through the yarn which leaves bits of snagged yarn over the finished garment.

Lenpur: Made form wood pulp from sustainable sources it has thermo regulating properties that help keep you comfortable.

Linen: Made from flax, linen is a cool and very absorbent fibre ideally suited to summer garments. It is inelastic, strong, hard wearing and gets softer with repeated washing.

Merino Wool: This is wool from Merino sheep, a breed of sheep originally bred in Spain. Their wool was so highly prized that for many years it was a capital offense to export a Merino sheep out of Spain! Merino wool feels smooth and soft making it especially good for garments designed to be worn next to the skin. The downside of merino is that is does tend to pill. For more general information see ‘Wool’ below.

Mohair: Mohair comes from Angora goats. It benefits from gentle hand washing. The resulting fabric isn’t very durable as it tends to pill. It definitely isn’t a fibre for beginners, but for the more advanced knitter the lure may be irresistible. You can’t beat the look and feel of mohair lace work. The fluffy nature of the yarn gives a kind of glow around the fabric. Kid mohair is softer but not as lustrous as fibre from older goats. Hand wash.

Possum: Made from the fur of culled New Zealand Possums. The animals are not native to New Zealand and are very destructive to wildlife, hence the annual cull. The fibre is hollow and so has thermo regulating properties. Not suitable for vegetarians.

Qiviut: Pronounced kiv-ee-ute, it comes form the Arctic Musk Ox. It is several times warmer than wool, a fine, soft, and very expensive yarn. Pure qiviut doesn’t felt. It can be produced by collecting shed fibre, the combing of domestic herds or from the annual cull of musk ox.

Wool: Pure wool may be expensive but it’s lovely to knit with and ideal for the beginner. It has an elasticity to it and minor problems with tension and fit can often be solved when the garment is blocked. The elasticity of wool makes it an essential ingredient in many yarn blends.

Wool is mildly water repellant and can absorb a good deal of water before it starts to feel wet. Wool is also lovely to wear; thermo regulating it also wicks moisture away from the skin and most wool yarns on sale these days are nice and soft.

Wool needs to be properly cared for (see our section on caring for your knitwear) to avoid it shrinking. The tendency for wool to shrink can be used to make felted knits, these can be great projects for beginners – see our knitting project section. (See also Superwash Wool). Wool is also the fibre of choice for stranded knitting and intarsia colour work because the scales on the wool fibers helps the yarn to grip together.

Different breeds of sheep provide wool with different qualities such as durability, softness, resistance to pilling etc.

Seacell: This is a new fibre made from seaweed and wood pulp.

Silk: This luxury fiber has beautiful sheen and drape but needs to be handled with care. Pure silk is slippery so the stitches easily loose their shape and so the knitting stretches and doesn’t return to its original size, so it’s best used for luxury rather than everyday items. Knit to a tighter tension / gauge than you would normally, avoid stocking stitch and only use very smooth bluntish needles. Silk blend yarns are easier to deal with and can give you the best of both worlds. Some silk yarns have a distinctive smell. See our tips for removing the smell from silk yarn. Not suitable for vegetarians.

Superwash wool: This can be washed in the washing machine on the wool cycle, some brands can even be tumble dried. Superwash wools can’t be felted and it isn’t as easy to correct minor problems when blocking, but being able to throw your knitwear in the washing machine is a great boon, especially for children’s knitwear.

Suri Alpaca: Only about 3% of alpacas are Suri Alpacas, so Suri yarn is an expensive luxury. Suri fibre lacks the crimp of the traditional Huacaya Alpaca fleece but has more lustre. An inelastic fibre that is most versatile when blended with wool.

Synthetic yarns: Novelty yarns aside, these are usually cheap and machine washable. Most have a small amount of stretch to them. The main downside tends to be that some aren’t as breathable as natural fibres. It may be better to go for a mixed fibre yarn for close fitting garments.

Vicuna: In the past vicuna yarn was reserved for Incan royalty. Vicuna yarn is scarce and expensive. It is shorn from wild vicunas, which are related to llamas, that live in the high Andes. An adult vicuna produces less than 500g of fiber a year. The hollow, air-filled fibres are very fine and the yarn is prized for its exceptional warmth.

Fibre Blends:

These are often great value for money. Look at the properties of all the constituent fibres to see if it’s likely to have the properties you are looking for. If there are no washing instructions then follow our instructions for washing knitwear.

3. Substituting Yarns

The usual advice is to knit a swatch and check you get the same tension / gauge as for the recommended yarn. But this advice doesn’t help with choosing which yarn to buy.

The first step is to get all the useful info you can on the recommended yarn: Yarn weight category, yarn texture (eyelash,plied etc), length of yarn per ball, fibre content and standard tension / gauge. Yarndex.com is a good starting point. The closer you want the finished item to resemble the original pattern the closer the match for the original yarn you should get.

Look for a yarn with a recommended stitch tension / gauge the same as or close to that for the recommended yarn (the row tension / gauge isn’t as critical). Be aware that some yarns quote the tension in stitches per inch while others quote stitches per 4 inches or 10cm. If you can’t find this info, then picking a yarn in the same weight category means you should be able to adjust the tension / gauge to match the recommended tension / gauge. Our chart of yarn weight equivalents can help with this (see section 1 above). Remember that lace stitches are generally knit on larger needles than those recommended for stocking stitch so the pattern stitch tension may lead you astray.

If the recommended yarn is a novelty yarn such as eyelash yarn, you’ll probably want to find a yarn with the same texture. You can substitute with a standard yarn as long as the tension / gauge matches, but the resultant fabric will be very different. The converse is also true, you can substitute a standard yarn for a novelty yarn if the stitch tension / gauge matches, but be aware that highly textured yarns will often obscure stitch patterns and the look and feel of the finished fabric will be very different too.

It’s also worth thinking about the fibre content too. Take a look at the yarn fibre section and think about how the differences will effect the final product. A ribbed jumper pattern designed for wool can be made in cotton, but it won’t be as stretchy or as warm and it will likely be heavier too. Substituting a wool yarn for a wool blend yarn is more likely to give a satisfactory result.

Another useful tip is that you can use 2 strands of a lighter weight yarn as a substitute for a heavier weight yarn. (This is a general rule of thumb, you will still need to make a gauge swatch!)

  • 2 strands of 4-ply yarn is equivalent to DK
  • 2 strands of DK can be substituted for Aran weight
  • 2 strands of Aran weight can be substituted for Chunky weight yarn

See the chart below for a full list of possible yarn weight equivalents.

One strand of this type of yarn Can be substituted with 2 strands of:-
Standard Weight 1
Superfine, Sock, Fingering, Baby, 2-ply, 3-ply
Standard Weight 0
Lace, Fingering
Standard Weight 2
Fine, Sport, Baby, 4-ply, 5-ply, light DK
Standard Weight 1
Superfine, Sock, Fingering, Baby, 2-ply, 3-ply
Standard Weight 3
Light, DK, double knitting, Light Worsted
Standard Weight 2
Fine, Sport, Baby, 4-ply, 5-ply, light DK
Standard Weight 4
Medium, Worsted, Aran, Afghan
Standard Weight 3
Light, DK, double knitting, Light Worsted
Standard Weight 5
Bulky, Chunky, Craft, Rug, Heavy Worsted
Standard Weight 4
Medium, Worsted, Aran, Afghan
Standard Weight 6
Super Bulky, Roving
Standard Weight 5
Bulky, Chunky, Craft, Rug, Heavy Worsted

Remember that if you substitute a yarn with 2 strands of a lighter yarn you will need double the length of yarn. So, 100m of Chunky weight yarn can be substituted with 2 strands of Aran weight yarn but you will need approx 200m of the Aran weight yarn.

Now you’ve done all that you can use our knitting calculator to work out how many balls of your substitute yarn you will need. This needs to be calculated from the length of the yarn and not the weight.

If you use 2 different colours you can get fantastic colour effects. See ‘Knit so Fine’ in our book reviews.

Finally, knit a good sized swatch and be honest when measuring your tension / gauge. Don’t be afraid to change needle size to get the correct tension / gauge. If the pattern uses more than 1 needle size e.g. a smaller size for the ribbing, but only gives tension / gauge for 1 needle size you might want to use our knitting calculator to estimate the best size to use.