We hear from lots of you that sewing with knits is a stressful prospect, which keeps you from taking on fun projects like making undies, bralettes or t-shirts!
Sewing with Knits
Here are some tips to keep in mind which will help you achieve the best finish when working with knits:
• Ensure you’re using a ballpoint or jersey needle in your sewing machine to prevent snags and pulls
• If you’re using a serger/overlocker, adjust your differential feed to suit your fabric
• Make sure you do not stretch your fabric as you sew, except where there is ease. Even while easing, do not overstretch
• If you’re using a serger/overlocker, go slowly and keep checking that you don’t accidentally have a tuck in your fabric. Cutting a hole in your garment is no fun at all (but absolutely happens to everyone once in a while!)
• Press as you go, using lots of steam. Check that your iron temperature is appropriate and use a press cloth if your fabric tends to mark (check on a scrap first)
• A neckline which looks wavy (but free of tucks or other serious issues) and will look much better with a good pressing and steaming!
What's the deal with 2-way and 4-way stretch?
You'll hear terms like 2-way stretch and 4-way stretch thrown around on the internet, but often fabrics won't be labelled that way online or in brick & mortar stores. You can hear Leila chat about and show you some fabrics with 4-way and 2-way stretch on this video.
4-way stretch fabric has stretch and recovery that is equal in both the horizontal and vertical directions. Fabrics like cotton/spandex, bamboo/spandex, merino/spandex will normally fit this description
2-way stretch fabrics stretch in one direction, usually from selvedge to selvedge (but can be in other directions depending on the knit), and also recover.
What's the stretch percentage?
The stretch percentage is the width of your fabric when stretched to its maximum, compared to its size when un-stretched
To test your stretch percentage, grab your fabric and a ruler. Put the edge of the fabric at 0 on the ruler and grab the fabric at the 10cm mark. Holding the fabric with both hands, stretch the fabric to its max and note what number on the ruler you've managed to reach.
If you get to 11cm, your fabric has 10% stretch, 12cm is 20% stretch, 13cm is 30% stretch and so on.
Cutting out knit fabrics
Some knit fabrics stretch out as you're laying them out to cut them. If you think that might be the case with yours, let it relax for a few minutes before you cut.
Ensure your knit fabric isn’t hanging off the edge of the table, stretching out! Your pieces might end up very small if you accidentally cut it stretched! You may wish to pool your excess fabric at the end of your table to prevent this.
If you are using a very slippery fabric, you may find it easier to cut if you layer your fabric between two pieces of tissue paper.
Cutting the pattern singly (without folding the fabric in half to cut two pieces at once) may mean you can use a little less fabric, and might make cutting out a slippery fabric a little bit easier.
Needles for knit fabric
Make sure you get either ballpoint or stretch needles for working with knit fabrics. Universal needles are quite pointy and will ruin the knit fabric by piercing the fabric instead of pushing the loops of the knit fabric apart.
Another great needle for getting a great finish on t-shirts is the double needle (or twin needle)- these work on your regular home sewing machine, and add a double line of stitching similar to what you see on commercial t-shirts.
What stitch to choose?
Your sewing machine will most likely have a variety of stitches and is sure to have at least one that will work with knits.
The most common is the zig zag stitch, but check the manual for your sewing machine as it may have suggestions for which stitches to use with knit fabrics for your particular sewing machine model. Always test these stitches out on a scrap of the fabric you’re using so that you can check stitch width and length, as well as tension.In our instructions for all of our knit fabrics, we let you know the stitch width and length we recommend.
Knit fabric can easily get sucked down into the feed dogs when you start sewing it from the very edge. To avoid this, start sewing a centimeter or so in from the edge, backstitch to the edge, and then continue sewing regularly.
Finishing the edges of knits
The wonderful news is that knits don’t fray, so there's no need to finish off the edges if you don't want to. It's perfectly normal (if somewhat annoying) for jersey fabric to roll to the front- deal with this before the rolling gets too out of hand (generally fixed by hemming).
Seams look wavy?
Use your iron. A good press and a lot of steam can tame your wavy seams, especially necklines.Worried about necklines? Check out this sew-along video from Leila on Youtube.