How to Substitute Yarn in Knitting Patterns: A Step-by-Step Guide
We’ve all been there. You fall head-over-heels for a pattern - gorgeous stitches, a perfect silhouette, just the sort of project your needles are itching for. But then you look up the suggested yarn and… oh. It’s discontinued. Or it costs more than your weekly shop. Or maybe it’s just not quite you.
The good news? Substituting yarn isn’t just possible - it can be empowering. With a little know-how, you can confidently swap in something that suits your project, your style, and your stash.
This guide will walk you through the steps to successful yarn substitution, covering everything from fibre content to drape to (brace yourself) swatching. Whether you’re an old hand looking to stretch your skills or someone helping a newer knitter make sense of skeins, this is for you.
Step 1: Understand Why Yarn Choice Matters
Before diving into substitutions, it helps to understand what a yarn brings to a project. It’s not just about colour or thickness - yarn affects how your finished piece fits, feels, and flows.
Key considerations:
- Fibre content – Different fibres behave in very different ways. Wool has bounce; cotton stretches; alpaca drapes.
- Gauge – That magic number of stitches per 10cm ensures your project is the right size.
- Drape & structure – A shawl should flow; a hat should hold its shape. Your yarn plays a starring role here.
Think of it like baking: swapping butter for olive oil might work for some recipes, but it won’t win you Star Baker with a Victoria sponge.
Step 2: Start with the Pattern's Specifications
Before picking a substitute, get to know the yarn the pattern calls for. Think of it like researching a character before stepping into their shoes.
Look for:
- Yarn weight (e.g. DK, Worsted, Fingering)
- Fibre blend (wool, silk, alpaca, etc.)
- Meterage per skein (e.g. 100g = 200m)
- Gauge/tension (e.g. 22 sts x 28 rows = 10cm on 4mm needles)
Can’t get your hands on the yarn? Ravelry is a treasure trove for specs, reviews, and comparisons. Simply search for the yarn and you’ll usually find all the technical details plus helpful notes from other knitters.
Step 3: Match the Yarn Weight (But Don’t Stop There)
Matching weight is the starting point, but not the whole picture.
Why it matters:
- A lighter yarn may give you a loose, saggy fabric
- A heavier yarn can result in a dense, rigid finish
But beware: One DK is not always like another. The only way to be sure? Swatch (we’re getting there, promise).
If your chosen yarn is just outside the target weight range, you may be able to tweak your needle size or the pattern slightly. But for best results, stick close.
Step 4: Fibre Content & Fabric Behaviour
Here’s where things get interesting. Fibre content has a huge impact on how your finished item behaves. A jumper knit in cotton will feel completely different from one knit in wool - even if the gauge is spot on.
Common fibres and their traits:
- Wool – Warm, springy, good memory (bounces back into shape)
- Alpaca – Soft, warm, drapey, but with less elasticity
- Cotton – Crisp, great stitch definition, but heavy and can stretch out
- Silk – Glossy and elegant, adds weight and drape
- Bamboo – Soft and drapey, but often lacks bounce
Top tip: Try to find a substitute with a similar fibre blend—or at least similar behaviour. If your pattern calls for a wool-alpaca blend, don’t reach for pure cotton unless you’re also adjusting expectations and construction.
Step 5: Consider Drape, Texture & Project Type
Drape is the unsung hero of great garment knitting. It’s what makes a shawl float or a cardigan cling just-so.
Ask yourself:
- Does the piece need to hang (e.g. shawl, cardigan)?
- Or hold structure (e.g. hat, socks, textured jumper)?
- Will it showcase texture (e.g. cables, lace)?
Quick guide:
- Need drape? Alpaca, silk, bamboo blends work beautifully.
- Need structure? Wool, mohair, and certain cotton blends keep shape better.
It’s not just about how it knits up - it’s how it wears.
Step 6: Swatch Like You Mean It
Ah yes, the dreaded swatch. But you know this already - swatching is a small effort for a big payoff. Especially when you’re subbing yarn.
How to swatch smart:
- Knit a generous square (at least 15cm x 15cm)
- Use the needle size recommended in the pattern
- Wash and block the swatch as you would the finished item
- Measure gauge, observe drape, and assess fabric feel
Swatching is like a first date. You don’t really know what you’re getting into until you’ve spent some time together.
If your gauge is off, don’t panic - try changing your needle size rather than giving up on your yarn entirely.
Step 7: Yardage Maths
Nothing halts knitting joy like running out of yarn two rows from the end. Let’s do the maths upfront.
Steps:
- Find the total yardage/metres needed for the pattern (e.g. 10 balls at 200m = 2,000m)
- Compare to your new yarn’s yardage per skein
- Divide to see how many skeins you’ll need (and maybe buy an extra, just in case)
If the new yarn has less yardage per skein, you’ll need more skeins. It’s not sexy - but it’s better than sleeve panic.
Step 8: Try It, Tweak It, Trust Yourself
You’ve checked the specs, matched the fibre, swatched like a boss… Now go for it. You’re not a beginner. Your instincts are seasoned. You know what you like - and what works.
Yarn substitution is a skill that improves every time you do it. It encourages creativity, resourcefulness, and flexibility - traits every knitter already has in spades.
And who knows? You might discover your new favourite yarn along the way.
Handy Yarn Substitution Checklist
Keep this in your project bag:
- Match yarn weight
- Check fibre content
- Evaluate drape & structure needs
- Compare yardage
- Swatch, wash, block, measure
- Adjust needle size if needed
- Trust your experience!
Your Knitting, Your Rules
At the end of the day, the pattern is a suggestion - not a law. With some thoughtful choices and a touch of curiosity, you can make it truly yours.
So next time you fall for a pattern but the yarn just doesn’t work out, take heart. You’ve got this.
Because you’re not just following patterns. You’re crafting stories - with every stitch.