Sewing with knit fabrics may seam daunting at first, but with a few tips and some patience you will soon master the techniques necessary to make beautiful, long lasting, and comfortable clothes for those you love.
You don’t need to use a serger or coverstitch machine for sewing with knit fabrics, though it can help up your game if you have them. If using a regular machine use a new stretch needle (this is my preference over jersey or ballpoint) and a walking foot to help feed the fabric through without pulling. The stretch needles are made specifically to work with this type of fabric and will help to prevent skipped stitches. If you are using a coverstitch, using a ballpoint overlock needle makes a difference in preventing skipped stitches as well. Check out this fun and FREE pattern in the shop which helps me keep all of my machine needles organized.
I have many knit patterns in the shop and in all of the sewing instructions there is of course mention of using a stretch stitch or serging the edges. Any stretch stitch will do, but the important thing to remember is not to use a straight stitch when sewing with knit fabrics. Even if the tutorial only mentions “stitching,” unless it is a basting stitch you should use a stretch stitch. A straight stitch isn’t meant to stretch so when the fabric is stretched (as when the garment is put on or taken off) the stitches will be stressed and the thread will break. There are usually many options with a regular sewing machine, but the most popular are the zig zag stitch and the “lightning bolt” stitch. The lightning bolt has been my favorite, but everyone seems to have their own personal preference so try a few and see what works best for you and your machine.
The most common issue with sewing with knit fabrics results from accidentally pulling the fabric too much or stretching the seams which can cause gathered or wavy edges. The only time I’d recommend stretching the fabric is when topstitching an opening like the neckline or at the wrist for a long sleeve. Even still, just a gentle stretch should be enough to allow the fabric to stretch around the opening, but still recover to the correct shape when worn.
Speaking of recovery, when working with knit fabrics it’s important to know the stretch percentage of the fabric and how well it recovers. This pattern recommends at least 40% 4-way stretch which means the fabric will stretch both with and against the grain. The vertical stretch is necessary for this particular pattern to have the correct fit as it was designed with 4-way stretch in mind. To determine the stretch and recovery percentages of your fabric, check out this post on Imagine Gnats.
The most important tip of all is to relax and not stress about sewing with knits. Practice makes perfect and we all started out with wavy, puckering seams our first go at it too. The good news is children’s clothing uses little fabric so a muslin shouldn’t break the bank. And the best thing about sewing with knits is that all of the stretch is actually very forgiving. Most “issues” won’t even be noticeable once the child is wearing the garment and the fabric is stretched so don’t stress in those late-night sewing moments when you think something looks terrible. Just wait until morning when it can be tried on to determine if a seam really needs to be unpicked. Good luck and happy stitching!