How to Substitute Yarns in Your Project

We’ve all been there. You find the perfect pattern, but the recommended yarn is either unavailable, out of your budget or simply not your style. The good news? Yarn substitution is easier than you might think! With a little knowledge and planning, you can confidently swap out yarns while still achieving a beautiful, well-fitting project.

In this guide, we’ll walk you through everything you need to know about yarn substitution, from understanding yarn weights and fibre content to matching gauge and choosing the right texture.

Why Substitute Yarn?

There are many reasons why you might need to swap out the recommended yarn in a pattern:

• Availability: The suggested yarn may be discontinued or unavailable in your area.

• Budget: You might be looking for a more affordable alternative.

• Fibre Preferences: Some fibres can be itchy, heavy or not suitable for certain climates or sensitivities.

• Eco-Friendly Options: You may want a more sustainable yarn choice, such as recycled or plant-based fibres.

• Personal Style: You want a different colour, texture or finish for your project.

Whatever the reason, substituting yarn is all about making sure your final project still looks, fits and functions as intended.

Step 1: Match the Yarn Weight

One of the most important factors in yarn substitution is choosing a yarn that’s the same weight as the original. Using the wrong weight can drastically change the size, drape and feel of your project.

Understanding Yarn Weights

Yarns are categorised into different weight classes, from laceweight (very fine) to jumbo (super thick). Here’s a quick guide to common yarn weights:

Yarn Weight	Other Names	Recommended Needle Size	Recommended Hook Size	Uses
Cobweb lacce	1ply, thread	1.5-2.25mm	1.5mm-2.5mm	Lightweight shawls, lace knitting
Lace	2ply	1.5–2.25mm	1.5mm-2.5mm	Lightweight shawls, lace knitting
Light fingering	3ply	2mm-3mm	2.25mm-3.5mm	Lightweight shawls, delicate garments
Fingering	4-Ply, Sock	2.25–3.25mm	3mm-4.5mm	Socks, delicate garments, accessories
Sport	5-Ply	3.25–3.75mm	3.5mm-4.5mm	Baby items, lightweight garments
DK	8-Ply, light worsted	3.75–4.5mm	4.5mm-5.5mm	Sweaters, cardigans, blankets
Worsted	10-Ply, Aran	4.5–5.5mm	5.5mm-6.5mm	Scarves, hats, warm garments
Bulky	12-Ply, Chunky	5.5–8mm	6.5mm-9mm	Thick blankets, cozy winter wear
Super Bulky	14-Ply and up	8mm+	9mm+	Quick projects, oversized accessories

When substituting yarn, always choose a yarn that falls into the same weight category to maintain the overall structure and sizing of your project.

Step 2: Check the Gauge

Even if a yarn is the same weight, it may knit or crochet up slightly differently due to its fibre content, structure or how it’s spun. Gauge refers to the number of stitches and rows per inch in a swatch and is essential to getting the right fit.

How to Check Gauge

1. Look at the pattern’s gauge instructions. The designer will specify how many stitches per 10cm (4 inches) your swatch should have.

2. Knit or crochet a swatch with your substitute yarn using the recommended hook or needle size.

3. Measure your stitches per 10cm.

   • If you have too many stitches, your yarn is too thin, or your tension is too tight. Try using a larger needle/hook.

   • If you have too few stitches, your yarn is too thick, or your tension is too loose. Try using a smaller needle/hook.

4. Adjust as needed to match the pattern’s gauge.

   
   

Skipping the swatch might seem tempting, but a small gauge difference can result in a final piece that is too big, too small or doesn’t drape as expected.

Step 3: Consider Fibre Content

Different fibres behave differently, even if they’re the same weight. Fibre content affects drape, elasticity, warmth and durability, so it’s important to consider what your project needs.

Common Fibres and Their Properties

Fibre	Characteristics	Best For
Wool	Warm, elastic, durable	Sweaters, winter accessories, socks
Cotton	Cool, non-stretchy, breathable	Summer garments, home décor
Bamboo	Soft, silky, drapes well	Lightweight garments, shawls
Alpaca	Warm, soft, drapes well	Cozy garments, scarves
Linen	Crisp, breathable, strong	Summer tops, lacework
Silk	Lustrous, drapey, non-elastic	Elegant garments, luxury accessories
Acrylic	Affordable, lightweight, durable	Everyday garments, blankets, toys
Recycled Yarns	Eco-friendly, varied textures	Sustainable crafting

When to Blend or Swap Fibres

• If a pattern calls for wool, but you want a plant-based alternative, try cotton or bamboo, but be aware it may have less elasticity.

• If a pattern calls for alpaca, but you need something lighter, try wool blends for warmth without the extra weight.

• If a pattern calls for silk, but you want something more affordable, consider bamboo or mercerised cotton for a similar sheen and drape.

Step 4: Consider Yarn Construction & Texture

Beyond weight and fibre, yarns are spun in different ways, which affects their stitch definition, drape, and overall look.

• Plied Yarns (2-ply, 3-ply, etc.) – These are strong, smooth and great for stitch definition. Ideal for cables and lace.

• Single Ply Yarns – Soft with a more rustic feel, but less durable. Better for accessories than high-wear items.

• Bouclé or Textured Yarns – Can add visual interest but may obscure intricate stitch patterns.

  
  

If your pattern features lacework or cables, avoid fuzzy yarns like mohair, as they can hide stitch details. If you’re making a structured garment, avoid very drapey yarns like bamboo, which can cause stretching.

Step 5: Adjust the Yardage

When swapping yarns, always check the yardage or metres per skein rather than just the number of skeins. Different fibres have different densities, meaning 100g of wool may not have the same length as 100g of cotton.

How to Calculate Meterage

1. Check how many metres of yarn the pattern requires.

2. Compare it to the length of your substitute yarn per skein.

3. If needed, adjust the number of skeins you buy to ensure you have enough to complete your project.

   
   

Example:

• The pattern calls for 5 skeins of yarn with 200m per skein → total 1,000m needed

• Your substitute yarn has 150m per skein → you’ll need 7 skeins instead of 5.

Final Tips for Successful Yarn Substitution

• Read project notes: If using a pattern from Ravelry or another platform, check project pages to see what yarns others have successfully substituted.

• Consider stretch and recovery: Some yarns stretch and bounce back differently, which can affect fit (eg. wool vs. linen).

• Be open to experimentation: Swatching is your best friend! If a yarn looks like a great match but behaves differently in your swatch, adjust your gauge or try another option.

• Ask for help: Your local or online yarn store or fibre community can be great resources for finding the perfect substitute!

  
  

Substituting yarn may seem daunting, but with a little know-how, you can confidently swap out fibres, match gauge and create a project that’s just as beautiful - if not more so - than the original. Whether you’re choosing a sustainable alternative, working within your budget or simply trying something new, the right yarn is out there for you.

At Fancy Yarns Australia, we stock a wide range of recycled, eco and novelty yarns, perfect for any project. Need help finding the right substitute? We’re always happy to help!