The stretch gauge is something I started using years ago to make my knitted hats. It’s something I came up with to make better fitting hats. I’ve never read about it or heard of anyone else doing it.
I’m going to jump right into the heart of the matter, and answer the question:
What is a stretch gauge?
A stretch gauge is when you take a normal gauge swatch, and stretch it out, either to maximum stretch capacity, or to the elasticity that you would like the finished knitted piece to be when it is worn, and then take a gauge measurement from the stretched out swatch.
How do you get the final measurement from the stretch gauge?
This takes some math. For example I started to make a cabled hat the other day.
The gauge in stockinette stitch was: 18sts=4in(10cm) and once I took the same swatch and stretched it out the stretch gauge was: 11sts=4in(10cm)
My head is about 21.8in(55.5cm) around.
So I need to do the following calculation. How many sts do I need in the stretch gauge to get 21.8in(55.5cm)
To find this, I take the stretch gauge and figure out how many stitches per inch, and then multiply that by the number of inches it is around my head.
So (11sts/4in)x21.8in= 59.95sts
For the best fit with my stretch gauge, I should cast on about 60 sts for the brim. In general I will usually cast on for a little bit looser fit than my stretch gauge, but never tighter. To calculate it so that it works with the cable pattern, I need to cast on 64 sts. This is close enough that it won’t make a big difference in final fit.
To compare, if I were to do a negative ease calculation I might do 2 inches of negative ease with my normal gauge. (18sts/4in)x20in= 90sts for the cast on. This is how most designers calculate for size. As you can see there is a huge difference in the number of stitches compared to the stretch gauge calculation. The final hat for the calculation will be much looser, and it might fit some people well, but I know from my stretch gauge that I personally want it to be the tension that I stretched it out to.
But why do a stretch gauge? Is it necessary? Won’t it be too tight? And can’t you just use negative ease?
There are a few really good reasons to do a stretch gauge and it gives you a lot more control over the fit of the finished piece than negative ease. I’ll break down some of the reasons.
- Fitting curly/kinky/thick haired heads.
My dad is from North Africa, and the most obvious trait I’ve inherited from him is his thick curly hair. It is voluminous and wild on good days. When I first started knitting, the hats I made from other designers would comically stretched out as soon as I put them on. The mushroom head look is not a flattering one, and it doesn’t keep your head all that warm. It was disappointing and disheartening, especially since I was new to knitting, and the hats took me so much time to make.
It is an unfortunate reality that I and all the other people with thick curly hair, or afros, or dreads, can’t easily find hat patterns to fit us well. Most hats are designed by people with straight or non-thick hair and made to fit people with similar hair.
Using the stretch gauge is one way to make a hat to fit someone with very thick curly or kinky hair since you can calculate and make a hat with just enough tension to fit your head and pull in all your hair. There are a couple points to doing this well. First you need a thick enough yarn, anything worsted or up should work. Then you need to size down needles to reduce elasticity. If the knitted work is too elastic then it will stretch out when it is worn, and you’ll look like you have a mushroom head. So for a bulky yarn, you might use US size 6 needles, or for worsted weight US size 3 needles. Then you knit a gauge swatch, and when you stretch it to take the stretch gauge, you are going to want to stretch it to maximum capacity for a fro-tamer hat, or to the point that you feel it’s tight enough to fit the head and smush the thick hair in. Once you have the stretch gauge, you calculate it to the persons head circumference (no ease calculation) and that should be the number of stitches that you cast on for the brim. Keep in mind that the stretch gauge is only used for the brim. Then an increase round is worked before continuing to the body of the hat.
2. Control over final fit
Even if you don’t have thick hair, when you measure the stretch gauge, you control exactly how much the knitted swatch is stretched. This means you can hold it in your hands and pull it out, and think. How will this feel against my skin at this point? Is this a good elasticity for a hat at this stretch point? If I try pulling it out further will it be too stretched out? Do I want it this tighter or less tight? At what point do I think the yarn looks and feels the best?
And then you can pinpoint exactly how stretched out you want the final hat or sock or whatever to be when you are wearing it. This is much more accurate than simply using negative ease, since there is a lot of difference in how the same negative ease feels with bulky yarn or fingering yarn, or even if you change the material the yarn is made from or how tightly or loosely you knit. This is a method for measuring size that gets rid of all those variables and simplifies it all down to looking and feeling and deciding from there. It’s a much more tactile and intuitive way of deciding the finished measurements.
3. Knitting with non-wool yarns (Alpaca, cotton, linen, acrylic etc)
Wool is elastic. It can stretch out over time when you wear it, but once you get it wet it bounces back to it’s original shape. However most non-wool yarns are not elastic, and once they stretch out, they are stretched out for good. This means if you make a hat using alpaca or cotton, then it might stretch out and become too loose to wear, and there won’t be any simple way to redeem it. However if you use a stretch gauge, you can stretch it out to it’s maximum stretch and calculate the size it needs to be. In short you are calculating and making something with the plan for it to stretch out to a better fit over time. This means that it might be a little tight at first, but as you wear it, it will stretch out to a comfortable fit.
So even if most hats you’ve made fit fine, and you don’t think that stretch gauge is something you need to use, it comes in useful when you are making a hat for someone with wool allergies or a cotton hat for a friend who wears hats all year round (We all know that one person…).
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