Week 2: Tension
Today Joanne takes us through what tension means. Tension (or gauge as it is sometimes known) tells us how large or small our stitches could be. In any pattern you will be given tension information. It will look something like this:
Tension: 18 sts and 24 rows in stocking stitch to 10 cm/4in using 5mm needles (or size needed to achieve tension)
If your tension is wrong then the finished piece will not be the size intended. To check whether your tension is correct for the pattern you will need to make a swatch. A swatch is a square of knitting using the yarn and needles you plan to use.
To prepare a swatch properly you will need to follow these four steps:
- Make a large square in the stitch you have been told to work in. To know that it will be large enough to measure you should cast on more than the number of stitches you can expect to get, In this case I would probably start with 24 stitches. Make the swatch in the yarn you plan to use using the needles you plan to use. Work a few more rows than suggested in the tension info, maybe 30 rows in this case.
- Measure the tension before you block it and keep a note so that you can check your tension while knitting. To measure the piece you will need to lay it out flat and count the number of stitches and rows in 4" or 10cm or the measure you were given. It may help to measure and pin then count between the pins.
- Wash and dry the piece as you will the finished object. So if it is going through the machine then the dryer do that. If it will be hand washed then dried flat do that. If it will be washed and pinned out to dry (blocked) do that. If it is cotton, silk, linen or bamboo it may help to hang the piece with weights attached (threading a dpn through the bottom is an easy way to do this) as these fibres grow considerably when the weight of the whole piece acts on the stitches.
- Measure again and compare this measurement to the tension information.
Hang on a minute, what does a stitch look like?
Each of the Vs in the picture above is 1 stitch. There are 22 1/2 stitches to 4 " in this picture.
How do your numbers compare?
If you have too many stitches/rows your finished object will be too small. Repeat the 4 step process with larger needles.
If you have too few stitches/rows your finished object will be too big. Repeat the 4 step process with smaller needles.
If you will be working in the round you should work the swatch in the round too.
I can get stitch gauge but my row gauge is off, what should I do? If you can only get one spot on then it is normally best to get the stitch gauge right as in most constructions this is where most of the fitting comes in. You may have to adjust the pattern slightly (adding or subtracting rows) to allow for the difference.
How much does it matter?
Well, how much do you want the finished item to fit? Say the tension square said 20 stitches to 4", your knitting is has 22 stitches and you go ahead and knit the jumper with the 40" chest. Your jumper finished jumper will have a chest measurement of just over 36" and you will have to suffer the indignity of finding a skinny friend to give all those hours of work to! Worth spending a little while before starting the project to avoid that fate? I think so!
Do I have to start with the suggested needle size?
No, it is just a suggestion based on the designers idea of what they used to get that gauge or what they think the average knitter will need to get tension. If you know you knit loosely you might want to try smaller needles first.
Afraid so! No two knitters work quite the same so even with the same yarn and same needles two people are unlikely to make the same tension.
So when don't I need to worry about tension? There are a few times when you can get away without swatching:
- When size doesn't matter and you have plenty of yarn (because tension also effects the yardage needed)
- When the item is very small and quicker to make than the swatch would be.