Created by Shannon McBride
Knit fabrics can take many different forms depending on the fiber contents and the specific knit process used to create them. Jersey Knits, Interlock Knits, Ponte de Roma Knits, ITY (Interlocking Twist Yarns), and Rib Knits are all very common knit fabrics used for fashion apparel. Throw in some Lycra Spandex in the already large variety of knit fabrics and that can be very intimidating to sewers!
But fear not, here are some tips and 3 solid stitches to sew easily with knit fabric!
A walking foot, also known as an Even Feed foot, will evenly feed the two layers of fabric through the machine at the same time. This prevents the fabric from being stretched out as it’s sewn, which is why it is ideal for very stretchy knit fabrics.
A walking foot prevents your machine from “eating” your fabric. Very lightweight knits, or very stretchy knits often will get pushed down into the machine when the needle punctures at the beginning of a seam when using a general purpose foot.
Knit fabrics that do not have that much stretch are actually better sewn using just a general purpose presser foot, which usually comes standard with the purchase of a sewing machine. The walking foot could actually feed the top layer too much, causing seam puckers.
When sewing with a regular sewing machine, I like to sew with a 3/8’’ seam allowance to ensure seam quality as it feeds through the machine, then trim down the excess. Knits will not unravel, so simply trimming them ¼’’ from the seam stitch will reduce bulk.
A serger is a special sewing machine that seams, trims, and finishes all in one. A 4-thread or 3-thread overlock stitch is very common for knit sewing. Sergers are ideal for knit garment sewing and give professional results.
Which needle to choose?
The right needle can make or break your knit project! If the right one is not chosen, you risk sewing frustration with skipped stitches, or damaged fabric from needle punctures. I advise to have a variety on hand. These color coded needles are my favorite!
Ball Point Needles :These are best, as opposed to a sharp needle, stretch needle or universal needle. The tip of the needle is smooth and rounded, so it can glide through the knit fibers, instead of piercing any fibers like a sharp (regular) needle could.
Stretch Needles: Stretch needles have a slightly less rounded tip than Ball Point needles do. However they do have a longer scarf, so they can go slightly deeper to catch the bobbin thread. If you are getting skipped stitches on your knit project, try this needle.
Universal Needles: Universal needles have the same scarf length as ball point needles and a slightly less rounded tip than Ball Point needles do so that they can pierce woven fabrics also. These will work fine on knits, however, ball point needles are best for knits with Lycra Spandex, or knits with very fine fibers.
Machine needles perform best when new. After about 8 hours of sewing time, they should be replaced. They could dull or bend, cause skipped stitches, or risk a broken needle puncturing your fabric.
What machine settings to use are a big culprit of knit sewing anxiety. With the vast varieties of knits available, there’s no one perfect setting to configure. The best advice is to test on scrap fabric before sewing your project. This will save so much time not having to undo stitches, save your fabric, and ultimately, save your project!
For loftier knits or stable knits, like ponte or scuba knit fabrics, try a lower tension around 2 or 3. Around 4 is usually good for heavyweight knits. The 4-5 Tension range generally yields the best results with light to medium weight knits. If you have to use a tension above 6, your machine probably needs servicing.
Longer stitch lengths cause less warp on knit fabrics. Even though straight stitches should not be used for seams, straight stitches set to 4 stitch length can work for topstitching. Shorter stitch lengths (1.5 – 2) should be used with a zig zag stitch to ensure that fabric doesn’t pucker out of the zig zag when the seam is pulled.
Applicable to zig zag stitches, 4-5 creates a deeper, wider zig zag, and around 1-2 creates a narrow zig zag stitch.
Every machine is different depending on its condition, so again, always test first!
A regular straight stitch will usually not work well for sewing seams with knits, especially Lycra Spandex knits. There are ways to manipulate the fabric as you sew, but it is not ideal and will not yield the best results. It may sew nicely, however, but when put to the test, the seam will easily pop and break once stretched:
Zig Zag stitch:
A simple zig zag stitch will allow the seam to stretch without popping:
Zig zag stitch across the grain with standard presser foot (not recommended, it stretches the fabric):
Zig zag stitch, sewn across the grain with walking foot (recommended for stretchy fabrics):
Narrow Zig Zag Stitch:
A narrow zig zag stitch can be achieved by setting both stitch length and width low, while on a zig zag setting. This stitch can closely mimic the look of a straight stitch, allow the seam to stretch with the fabric, increase sewing speed, and reduce bulk in the seams allowance. This stitch is not recommended for skin-tight garments like leotards or leggings because when the seam is pulled tight, it will have a ladder appearance.
A narrow zig zag stitch with a general purpose foot:
As you can see, the seam worked beautifully without the need of a walking foot since this fabric doesn’t have much stretch:
Narrow zig zag stitch on stretchy fabric, used a walking foot:
Stretch Straight Stitch:
Not all sewing machines have a stretch stitch setting, especially older ones, but most machines made within the last 10 years have a stretch setting. A stretch straight stitch is a series of forward and backward stitches that allow the seam to stretch, but with the appearance of a regular straight stitch.
A downside to using this stitch is it is almost impossible to take the seam out if you’ve made a mistake. Seam rippers, scissors and time might get it out, but the quality of the fabric will likely be damaged and warped. Another downside is that it takes longer to sew. Since the stitch itself is made up of several stitches, the speed of which it feeds through the machine is slower. This seam, however, gives great results when properly used!
Stretch Straight Stitch, with a general purpose presser foot:
Stretch Straight Stitch with a walking foot, because this grey rib knit fabric is super stretchy:
This fabric is super stretchy with 75% stretch, and there is only very minimal ruffling from using a walking foot with a stretch straight stitch. The image below is the result AFTER I pulled on it significantly. Success!
Without a walking foot (Not recommended, too hard to control stretchy fabric):
Our Favorite Knit Fabrics
Our Pattern Picks for Knits:
- Sew Over It Heather Dress
- Ralph Pink Roxy Dress
- Jamie Christina Mission Maxi Dress
- Grainline Studio Penny Raglan Tee
- Cashmere Dartmouth Top
- Megan Nielsen Axel Skirt
- True Bias Hudson Jogger Pant (they have a Hudson Jogger pattern for kids, too!)
- Simplicity 8212 Leggings
Happy sewing with knits!