• Michelle

Yarn Substitution Mini-Series Part 2: Swatching

Updated: Aug 13

Following on from my previous post about yarn substitution, where I probably used the word swatch more than is polite, it is time to talk about swatching. In this post, I’ll cover:

  • What is swatching & why is it important

  • How to swatch

  • Options for when you don’t get gauge

What is swatching & why is it important


When I say the word swatch I often feel like I am lifting the corner on Pandora’s box! You never know what’s going to happen so I am going to stick to the facts. No one likes to be reminded of the ill-fitting garments they have tucked out of the way ; )


What is swatching


Swatching is knitting a gauge swatch/tension square in the yarn and needles that you are planning to use for a pattern to see if you get the same number of stitches and rows per inch/cm as the pattern.


The number of stitches and rows that you get per inch/cm is referred to as gauge (or tension). Getting the same number of stitches and rows as the pattern tells you that if your gauge stays the same throughout, your knits finished measurements should be the same as those on the pattern, for the size that you are making.


Not getting the same number of stitches and/or rows tells you that you won’t get the same measurements and may need to make adjustments to ensure you get the size you want.


That’s it. It doesn’t tell you that you are a good/bad knitter, doomed to failure, full of virtue or anything else : ) Just the knit facts!

This is the yarn and gauge detail from Simply the Simplest Sweater DK (included with Knit School). At no point are you being scolded, just informed as to how to get the sweater you are expecting ; )


Why is gauge important?


Gauge is the cornerstone of the pattern that you are knitting (and almost all other patterns). As a designer, after I work out broadly what I am designing, I knit a swatch or multiple swatches in the yarn and needle size that I am planning to use in the design. These swatches are the basis for almost all of the calculations that are then done to design the pattern. It includes how many stitches to cast on, when and where and by how many to increase or decrease, even down to how much yarn the pattern will require. This is one of the key reasons why swatching to check your gauge is important.



This is part of my grading spreadsheet for Simply the Simplest sweater. The first detail I add, after the sizes, is the gauge. Most of the calculations in the sheet are based on those two numbers.


A little mathematical example (feel free to skip)


I am often asked if one row or stitch of a difference over 4 inches really make a difference? As a general rule, the larger the knitted item, the more small differences in gauge will be noticed (anecdotal experience only).


A calculated example:

  • I knit a swatch in the needles and yarn recommended by the pattern.

  • My gauge has ½ a stitch more per inch, 8 stitches to 1 inch instead of 7.5 stitches to 1 inch.

  • The pattern tells me to cast on 300 stitches. At the correct gauge, this would be 40 inches. However, as my stitches are smaller, 300 stitches will only measure 37.5 inches.

  • Applied to a bust measurement, that 2.5 inch difference in size may be the difference between a sweater you love and a sweater that is never worn

It is useful to think of what you gain by spending a little time doing a swatch. An hour spent knitting a swatch for a chunky snood that you will knit in 4 hours may not be worth it but an hour spent knitting a swatch for a 4ply sweater that may take you 80 hours is very different.


Block it like you'll wear it


An underrated part of swatching is the blocking process. When you treat your swatch like you will the finished knit, you get a much better understanding of how the fibre behaves and if it is truly suitable for the project you want to make with it. In a similar vein to the words ‘Drive it like you stole it’, I am a great believer in block it like you wore it! Planning to machine wash the garment? Machine wash the swatch and so on.


What if there is no gauge on the pattern?!


The designer is pretty confident that you will get something resembling the pattern and that you won’t run out of yarn. I am guilty of this in some of my earlier designs, before I found the tech editor of my dreams! : ) In these situations, you have the option to check your own gauge. You can do this to check if you like how the fabric feels or you can do some rudimentary maths to see if you are likely to end up with the same size as the designer is predicting you will.

Before I found the world's best technical editor .. there is no way she'd have let me away with this!

How to swatch


Before swatching, ask yourself what you are trying to do with the swatch. Are you going to do anything with it? Or are you just going to proceed anyway?

  1. Using the pattern as a guide, cast on a number of stitches that will give you a piece of knitting that is at least 5 inches wide (I recommend between 6 and 8 but that’s pushing it)

  2. Use the needle recommended in the pattern, if you are using a yarn that you think will substitute well, otherwise use a needle that is recommended on the ball band of for yarn of that weight

  3. Knit the swatch in the stitch that the pattern tells you gauge was achieved in. A stocking stitch swatch won’t tell you anything if pattern gauge is measured in a delicate lace motif

  4. If the pattern is knit flat and the gauge in the pattern was given as flat, then knit the swatch flat. If it was given in the round, knit the swatch in the round

  5. Wash your swatch in the way that you are intending to wash the final garment. If you are unsure how that will be, full wet block your swatch

  6. Soak in water for 15 minutes

  7. Using a towel, remove the excess water

  8. Pin the piece out flat. Don't stretch or pull it excessively

  9. Wait until it is completely dry

  10. Measure the number of rows over 4 inches (use a rigid ruler for greater accuracy)

  11. Measure the number of stitches over 4 inches (see about above a rigid ruler)

  12. Label your swatch with the yarn and needle size used, the stitch knit and the gauge achieved

  13. Compare your gauge with the pattern gauge

A flat surface and a few pins are all you need!


A little note: Swatching is not infallible so even if you do get gauge, continue to check your measurements throughout your project to ensure you are still on track. This is also the case if you don’t swatch. You can tell quite quickly if your garment is too wide/not wide enough etc. Honest!


What to do when you don’t get gauge

There are 7 options that I believe are available if your gauge doesn’t match that of the pattern:

  1. Your Gauge is wrong

  2. Do nothing and accept it, decide that you are knitting the item regardless OR decide to make something else

  3. Your swatch has less stitches/rows

  4. This means that they are bigger than the stitches/rows in the pattern. Try a smaller needle to see if you can get closer

  5. Your swatch has more stitches/rows

  6. This means that they are smaller than the stitches/rows in the pattern. Try a larger needle to see if you can get closer

  7. You have stitch gauge but not row gauge

  8. Locate the parts of your pattern where row gauge is important and adjust these parts of the pattern only

  9. You have row gauge but not stitch gauge

  10. Try a different needle size as compensating for stitch gauge can be trickier

  11. Your overall gauge is a percentage smaller/bigger than the pattern gauge

  12. Work out if you can make a % bigger/smaller size that will give you the size you need

  13. You cannot get gauge but really want the pattern in the yarn that you have chosen

  14. Reverse engineer the pattern. You can work out how the designers gauge relates to all the stitch, row, increase, decrease etc sections of the garment and then work out how to change these to work for your gauge.

And that take us very neatly on to Knitting Maths which I will cover in the next post.



Before I go, just a little note on how to make swatching easier for yourself:

  1. Think of it as part of your project and not just a chore you have to do

  2. Remember that you can reuse it for other projects if you like the yarn so it’s not a waste of time

  3. Know that you are more likely to get what you see in the pattern pictures

  4. Do it while doing something where you couldn’t be knitting anything else (this is harder for sock knitters because there it is always sock knitting time ; ))

  5. There’s no Swatching Police, knitting should be enjoyed so swatch or don’t swatch! Knit your way!


I did not swatch for this sweater ... but I had used the yarn with the needle sizes before so I had kind of swatched ; )


Now I'm sure I can find something to swatch if I just look hard enough ; )

Michelle x

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