Tips on figuring out how to Substitute one yarn or thread for another

I’ve been getting a lot of questions from people, asking for help about how to substitute one yarn for another. They want to know if a different yarn than the one that is listed in a pattern will work or not.

Well, there are a couple of ways of figuring that out.

First one: WPI: Wraps Per Inch.

This is a weaver’s trick:

The pattern calls for one particular yarn.

But, what if someone else has a cupboard full of something else?

What will the pattern look like in one of those yarns?

Are they compatible with the pattern?

Here’s where the comparisons start:

Take a ruler, and wrap the yarns in question around the ruler. Snug the wraps up against each other for 1 inch. (2.5 cm). It doesn’t matter how big your ruler is, you just want to see the yarn politely laying there, showing you how thick or thin it is.
Now, count how many wraps there are in an inch.

I’ve shown 3 different yarns in this photo:

photo by Noreen Crone-Findlay copyright

The Lion Cotton has 14 wraps in each inch, the Microspun has 15 and the Crochet Cotton has 34………..

Important information! It tells you that the Microspun and the Cotton are pretty close in thickness, and that the Crochet cotton is less than 1/2 the thickness. Useful!

Next:
Look at the gauge information on the label:
Lion Crochet Cotton: Gauge: 28 sc st and 36 rows =4″ (10cm) x 4″ (10cm) with a Size D-3 (3.25mm) hook

Lion Cotton: Gauge: 16 sc st and 16 rows =4″ (10cm) x 4″ (10cm) with a Size F-5 (3.75mm) hook

Lion Microspun: Gauge: 13 sc st and 16 rows =4″ (10cm) x 4″ (10cm) with a Size H-8 (5mm) hook

And then, try a swatch. Swatches are your friend!
Work with the hook listed on the label. You may decide to change it, but it’s a good place to start.

Use the recommended hook for each of the yarns and crochet a sample swatch.

Often, you’ll make a square, but making something close to what you will be ultimately creating will also give you a lot of information.

You can get lots of info by crocheting or knitting or weaving small motifs:

photo by Noreen Crone-Findlay copyright

What do you learn by doing this? What size hook or needle gives you the gauge you want?  If it feels or looks too loopy,  I would go down  a size, or maybe even smaller.

If it feels really loose, perhaps add another strand of yarn.

If it feels too tight, go up a size or two with your hook or needles.

What else? That the hook or needles listed on the yarn label might not give you the gauge that you need to make your pattern work.

AND: The 2 larger butterflies are identical in size. SO, if the pattern had been written for one of them, I could easily switch over to the other yarn and appropriate hook.

They don’t look the same in the pic above, so I took another with one on top of the other to show that they really are:

photo by Noreen Crone-Findlay copyright

What do you do if your yarn is way thicker than what is called for in the pattern?
Can you use it? Sure. You can split some yarns into individual strands.  Some yarns split really easily, some are nasty. You’ll have to experiment
OR: You could go ahead, and work the pattern as written, using thicker yarn and a larger hook….. and you’d get much larger motifs. You would simply make a whole lot less of them.

I hope that this will help you decide which yarn is going to work best for you!

Image source: Noreen Crone-Findlay copyright