Using WPI to Substitute Swatch a Special Yarn

Special yarn is often tricky to swatch. I have been intimidated by yarns in my stash. Logic doesn’t always play into it.

I know that I need to swatch, I write about it all the time! First, it helps me to understand the fabric in my chosen stitch pattern and needle/hook size, I call this a fun(damental) swatch. Another very good reason is to figure out the size of the fabric I’m creating with that very same stitch pattern and needle/hook, this is the infamous gauge swatch. Sometimes they can be the same swatch, but that’s a different discussion.

My issue with special yarns is that even though working with yarn doesn’t have the same finality as cutting fabric, I’m still often hesitant to swatch because it often feels that way! I warned you that logic doesn’t play into it.

I’ve developed a few ways to swatch a yarn without actually swatching it. This method lets me work on a few initial swatches that I’m not worried to rip back and try something else. Once I have a good idea what I think will work, then I do generally swatch with my special yarn.

How do I perform this magic?

I find a substitute yarn!

When substituting one yarn for another you generally want to keep as many of the same characteristics as possible — fiber, weight, construction, and even hinting to the colorway. With some special yarns, specifically with handspun, that can be challenging to find in one yarn. In this case I find a few yarns that meet different criteria, and create multiple swatches to help answer different swatch questions.

For example, lets work on this skein of my handspun. It’s from a braid of hand-dyed Bluefaced Leicester (BFL) that I spun in 2013.

Skein of dark teal handspun laying on a grass lawn
Handspun, October 2013

This yarn has been a challenge for me. The issues with it are numerous but the biggest is that it’s incredibly overspun, both in the singles and during plying. That means the texture isn’t a lofty soft yarn, it’s more akin to rope. I’ve tried many projects over the years and have ripped everything out.

First step – WPI

As a starting point, I need to determine the WPI, wraps per inch. This number will help to assign the weight category and narrow the search for similar yarns. There are many books and websites to find what a WPI means, I’ve added a few of my favorite books to the References.

cake of handspun and WPI tool with yarn wrapped around it on a plain white background
checking WPI with the handspun yarn

This handspun yarn has a WPI of 17, which makes it a fingering weight yarn. However, I know that number isn’t exact — there are long stretches where the yarn is thicker or thinner.

One potential for the substitute swatches is a yarn at the lighter end of that spectrum, this Anzula Cloud fits the criteria with 18 WPI. However, it has a completely different structure, my handspun is a 3ply and this is a very soft yet beautiful 2-ply.

Handspun ball of Anzula Cloud and WPI tool with yarn wrapped around it on a plain white background
checking WPI for the Anzula Cloud

My next yarn substitute is LGF Suris Sock, which is a 3-ply yarn. The alpaca is closer to the longwool staple of BFL, however this is a heavier yarn at 14 WPI.

Leftover cake of LGF Suri Sock in neutral white and WPI tool with yarn wrapped around it on a plain white background
checking WPI for LGF Suris Sock

How might these create helpful swatches? They’re two yarns I’m familiar with so I have a mental starting point for the kind of fabric they can create.

However the texture of my handspun is different. It’s a very dense yarn. In that category, cotton comes to mind and I have a cone of 3/2 mercerized cotton. It has a WPI of 17 which matches my handspun.

Cone of persian green UKI 3/2 cotton and WPI tool with yarn wrapped around it on a plain white background

This perhaps surprising substitute is a yarn that doesn’t have the same stretch and loft that the Cloud has. This will help me figure out how different stitch patterns may behave.

There are other yarns in my stash that I initially considered for substitutes. There was a lone (and discontinued) skein of a cotton blend, however despite its unique structure (4-ply), those plies are loose and it’s a worsted weight. When combined those two factors won’t help help me figure out this handspun.

Summary of potential substitutes

  • my handspun = 17 WPI, ~ Heavy fingering, dense 3-ply, BFL
  • Anzula Cloud = 18 WPI, ~ Light Fingering, loose 2-ply, blend of Superwash Merino, Cashmere and Nylon
  • LGF Suri sock = 14 WPI, ~sport, balanced 3-ply, blend of Alpaca, Wool and Nylon
  • 3/2 Cotton = 17 WPI, ~ Heavy fingering, balanced 2-ply, Mercerized Perle Cotton

While I don’t have a yarn that is an exact match to my handspun, but I think these three potential substitutes will help me better understand how it might work up into different fabrics. I’d like to have a successful project from yarn I created a long time ago!

Cake of dark teal handspun on plain white background


Please note that book title links are to and the authors are either to their website or their publisher.

Leave a Reply

Your email address will not be published. Required fields are marked *