At some point every knitter who felts will want to strike out on his or her own and design a felting project. While you might be comfortable starting out on a standard knitting project without knitting a gauge swatch, it's not a good idea to jump straight into a felting project because you never know how much a particular yarn will felt until you felt it.
For that reason, knitting and felting a gauge swatch is a great idea. You'll not only learn how a yarn behaves when knit and felted, you'll get to see how much a swatch will felt and what the yarn looks like after it's felted. Once you've done this a few times, you'll see that a yarn you love unfelted might not look so great to you when felted, or vice versa.
Here's how you go about making a felted swatch:
- Pick out a yarn that you'd like to felt. Choose knitting needles that are two or three sizes larger than the size suggested on the ball band.
- Cast on about 25 stitches, or enough to give you 5 or 6 inches of width in the yarn you are using.
- Knit in stockinette stitch for 40 to 50 rows. You want your swatch to be a big rectangle that's longer than it is wide, because felting tends to shrink more in length than in width.
- Bind off and weave in ends.
- Pin the swatch down flat and measure the length and width. Write these numbers down.
- Felt the swatch in the way you intend to felt the finished project. If you're going to felt it by hand, it's fine to felt your swatch by hand, but it's better to use the washing machine if you plan to felt your finished project in the machine.
- Keep track of how long it takes to felt the swatch, if you want. Pin out the felted swatch so that the sides are straight and allow it to try.
- Measure the swatch and compare these numbers to the original number.
Now that you know this information, how can you use it to develop your own felting patterns? The method I use to determine how big to make a project I'm planning to felt is using a simple calculation know as percentage change.
The way to calculate percentage change is to take the final number and subtract the first number from it, then divide by the first number and multiply by 100 to get the percentage change.
For example, if your swatch was 8 inches by 11 inches to start with and became 6 inches square after you felted it, your width shrunk 25 percent (6 minus 8 divided by 8 times 100 is -25) and your length shrunk about 45 percent.
This helps you because you can decide how big you want your finished project to be and plug numbers into the percentage change formula to make sure you're knitting enough so it will be the size you want after it shrinks.
Alternatively you can just look at what your finished swatch looks like and consider how much bigger you'd need to knit your project to get the finished size you need.
So if you cast on 25 stitches and they felted down to 6 inches, if you want your finished project to be 12 inches wide, you know you can cast on 50 stitches.
A little math is required to make your own felting projects, but if you start with a felted swatch, you'll be well on your way to making a felted project that you'll be happy with in the end.