You find a beautiful skein at the back of the cupboard. You simply cannot remember where it came from. The ball band is long gone, and now you are standing with an unknown yarn you cannot identify.
It is a classic problem in the knitting world. The yardage is unknown, the fibre content is a pure guess, and even the colour code is missing. You cannot simply look up a pattern and check whether the yarn works.
Fortunately, you can get remarkably far with a systematic approach. You do not need to know the precise details to be able to use the yarn. You just need to know enough to place it in the right technical category.
Visual identification
Start by getting the yarn under a good, direct light source to observe the physical details.
Yarn weight
The weight category does not describe how much the individual skein physically weighs on a scale. It describes the thickness of the strand. The Craft Yarn Council has a scale from 0 (Lace, very fine yarn) to 7 (Jumbo), and the thickness is the most important detail to establish. Nordic producers also use their own groups, for example DROPS’ A to F.
The most reliable method is to knit a swatch in stockinette. Make it large enough to measure 10 cm inside the piece, away from the selvedge stitches, and count the stitches per 10 cm. Note which needles you used. The numbers give you an indication, not a verdict: DROPS Kid-Silk is lace, but is knitted at 23 stitches on 3.5 mm, and both figures fit sport as well. That applies in particular to lace and hairy yarns, which can be knitted both densely and openly. If the yarn is going to a specific project, wash and dry the swatch first. Compare the result against the official Craft Yarn Council (CYC) scale:
| CYC | Category | Stitches/10 cm | Suggested needles |
|---|---|---|---|
| 0 | Lace | 33-40 sts | 1.5-2.25 mm |
| 1 | Fingering | 27-32 sts | 2.25-3.25 mm |
| 2 | Sport | 23-26 sts | 3.25-3.75 mm |
| 3 | DK | 21-24 sts | 3.75-4.5 mm |
| 4 | Worsted / Aran | 16-20 sts | 4.5-5.5 mm |
| 5 | Bulky | 12-15 sts | 5.5-8 mm |
| 6 | Super Bulky | 7-11 sts | 8-12.75 mm |
| 7 | Jumbo | ≤6 sts | 12.75+ mm |
This table is a guide. CYC and WPI do not measure exactly the same thing, so categories can overlap. Gauge and a swatch should always determine the final choice.
If you want a quick estimate without reaching for your needles straight away, you can use the WPI method (Wraps Per Inch). Wrap the yarn loosely around a ruler and count how many wraps sit side by side within exactly one inch (2.54 cm).
The number of wraps gives a rough indication of the category. The ranges overlap, so one number can fit several categories:
- 30-40+ wraps: Lace
- 14-30 wraps: Fingering
- 12-18 wraps: Sport
- 11-15 wraps: DK
- 9-12 wraps: Worsted
- 6-9 wraps: Bulky
- 5-6 wraps: Super Bulky
The WPI measurement becomes unreliable if you stretch the yarn or press the wraps together. Lay them side by side so they just touch, and measure in several places. Airy and hairy yarns are particularly hard to measure.
If you do not know the yardage, you can work it out. Measure a length of yarn without stretching it, weigh it, and convert for the rest: measured metres times 100 divided by the sample’s grams gives metres per 100 grams. The piece has to weigh at least ten times the smallest increment your scale shows, so if the kitchen scale shows whole grams, measure out at least ten grams of yarn. A short length of fine yarn weighs too little for the scale to read.
See the full overview of yarn weights and categories in the Guide to yarn weights.
Colour structure
A yarn’s colour typically falls into one of three categories:
- Solid: One homogeneous colour throughout the strand. The obvious choice for prominent cables and precise texture patterns.
- Marled: Two or more shades spun together in the strand, producing a soft, speckled colour play. It tends to obscure very complex patterns.
- Multi-coloured: Distinct, shifting colour sequences that are either industrially printed or hand-dyed in sections.
Sheen and light reflection
Hold the strand up to the light to assess the surface:
- Matte: Typically classic wool, cotton or dry acrylic fibres.
- Slight sheen: Fine merino, alpaca or blends with a touch of silk.
- High sheen: Viscose, Tencel and many silk yarns. Silk can also be matte, so sheen alone does not settle the fibre. Yarn sold as bamboo is usually viscose made from bamboo.
Sheen, halo and handle point towards a fibre group but do not prove it. Blends and finishing can give the same impression in different materials.
Halo
Halo describes the layer of loose fibres standing out from the core of the strand. Look at the yarn’s profile against a light background:
- No halo: The strand is smooth and sharp. Typically a worsted-spun wool, cotton or mercerised yarn.
- Moderate halo: Woolen-spun wool or shorter, softer wool fibres.
- Pronounced halo: Mohair, brushed alpaca, angora or kid silk blends.
What you can feel
Take the strand between your fingers, roll it back and forth, and feel its mechanical structure.
Softness and skin comfort
Feel the yarn against the inside of your wrist or your cheek to judge how it feels against your skin:
- Extremely soft: Superwash merino, cashmere and silk mohair can feel very soft against the skin.
- Soft: Standard merino, fine alpaca and soft wool blends.
- Medium: Everyday utility wool or cotton.
- Rustic: Heritage Nordic or Icelandic wool breeds (e.g. Lopi), which contain coarser outer guard hairs.
Yarn construction and twist
Pull gently on the strand and separate the fibres at the cut end to count the individual plies twisted around each other:
- Singles (single ply): One spun fibre strand that is not plied with others. The twist can be either loose or tight. It is vulnerable to abrasion and can bias slightly in stockinette.
- 2-ply: Two strands twisted together. Very common in fine wool yarns and fingering weight.
- 3- to 4-ply: Three or four plies twisted together. Often gives a round yarn with clear stitch definition.
- Cable-plied: Two or more already plied yarns twisted together again in the opposite direction. The parts can be either two-ply or three-ply. Produces a stable and durable strand.
Some yarns cannot be read by counting plies. Chainette is knitted as a fine tube, blown yarn is fibre blown into a tube, and bouclé has loops laid around a core.
Tests you can do at home
If you have a short length of yarn to spare, you can run two simple tests that give you a clue about the fibre type.
The burn test
Cut a yarn end of about 5 cm, hold it with tweezers, and carefully pass it over the flame of a tealight. Perform the test over a sink or a fireproof surface, make sure the room is ventilated, and do not breathe the smoke in directly when you smell it.
| Reaction in and after the flame | Remaining ash / residue | Fibre type |
|---|---|---|
| Smells strongly of burning hair. Burns slowly and often self-extinguishes. | Black, irregular ash that crumbles easily between the fingers. | Protein fibre (Wool, alpaca, silk, mohair) |
| Smells of burning paper or wood. The flame catches quickly and burns evenly. | Fine, light and greyish or white ash. | Cellulose fibre (Cotton, linen, viscose, bamboo) |
| Chemical smell of burning plastic. Melts and produces chemical fumes. | Often leaves a hard, black or dark melt bead. | Synthetic fibre (Acrylic, polyester, nylon) |
| Smells of paper, but the strand melts and pulls together. | Soft ash with small, hard beads. | Cellulose and synthetic blend (e.g. cotton/polyester) |
A blend can show signs of both fibres at once, for example the smell of burning hair together with the smell of plastic. How clearly each sign comes through depends on the blend ratio, which is why blends are hard to read. The burn test cannot reliably identify blended yarns, but it can help distinguish between protein, cellulose and synthetic fibres.
The felt test
Wet a short piece of yarn with lukewarm water, place it in the palm of your hand, and roll it vigorously against your other palm for about a minute.
- Result A: The fibres felt together completely into a firm, inseparable mass. The yarn most likely contains untreated animal fibre, often wool. That points to hand washing. If you want to felt a whole project, knit a swatch and felt that first.
- Result B: The strand simply gets wet, keeps its structure and slides apart without felting. The yarn may be superwash-treated wool, cotton, or a synthetic fibre such as acrylic. The test does not rule out felting in a real wash, and it does not tell you whether the yarn can go in the machine.
Wash a swatch and check for colour bleeding before you use an unknown leftover alongside other yarns.
How Nysta automates the process
Nysta has a guide for yarn without a ball band that asks the same questions as this article, for example about weight category, fibre, sheen and halo. If you don’t know an answer, you skip the question.
Then we suggest known yarns that match your answers. You can also add the yarn manually based on your answers, so Nysta can find patterns that suit the yarn.
We do not remove all uncertainty, but we make it possible to use a leftover skein you would otherwise leave sitting.
Download Nysta on the App Store and try it free for 7 days.
Frequently asked questions
How do I find out what my yarn is? A WPI measurement can help you estimate the yarn weight. Knit a swatch to check whether you match the pattern’s gauge. Then assess the fibre content with a burn test or felt test. That gives you a starting point for choosing a pattern. Also check that you have enough yarn, and that its properties suit the project.
What is WPI? WPI stands for Wraps Per Inch. You wrap the yarn loosely around a ruler and count how many wraps sit side by side within one inch (2.54 cm). The number gives a rough indication of the yarn weight category.
Can you identify fibre content at home? You can get far with two simple tests. The burn test distinguishes between protein, cellulose and synthetic fibres. If the yarn felts, that can point to untreated wool or another fibre that felts, but on its own it cannot establish the fibre content. Blended yarns are harder to identify with certainty.
Can Nysta help identify unknown yarn? Yes. A guide in the app asks about weight category, construction, fibre, sheen and halo, among other things, and suggests known yarns that match your answers. You can also add the yarn manually, so Nysta can find patterns that suit the yarn.
Add your yarn, including any without a ball band, and we’ll find patterns that fit.
Nysta is available for iPhone and Android. You can try it free for 7 days. After that, you can choose a monthly or yearly subscription, and you can cancel anytime.