The Ultimate Guide To Sewing With Knit Fabric

Are you keen to start sewing with knit fabric? Knit fabrics are an absolute joy to wear and sew with. Learning to sew with knits will open up countless options for a stunning, practical wardrobe, suitable for all seasons. Knit Fabrics often have a scary reputation when you first begin learning to sew. The traditional knits that were hard to find an in limited types and prints have been replaced by high quality easy to sew knits thanks to the custom fabric market. Knits are a joy to sew and easy to wear, it helps to know a little bit about best practice techniques before you turn on your sewing machine. 

In this guide, we’ll reveal little tips and tricks to help you feel confident sewing with knit fabric and how to successfully finish any knit sewing project.

What Is Knit Fabric?

In the world of fabrics, there are two main types of material: woven and knit. Woven fabrics are made on a loom by weaving together vertical and horizontal threads (known as the warp and the weft). Knit fabrics are constructed with a continuous loop of yarn to create an interlocking, braided appearance.

Characteristics of Knit Fabric

Knit fabrics are naturally stretchy. Certain fabrics have two-way stretch (stretching either horizontally or vertically) and others have four-way stretch (stretching horizontally and vertically). As a result, sewing patterns that use knits typically have something called ‘negative ease’.

In practical terms, this means a finished garment made with knit fabric will actually be smaller than your body’s measurements, stretching over the wearer’s body for an easy, perfect fit.

Knit fabrics tend to be highly pliable with excellent drape and a soft texture. Knits are faster to work with, but they can be trickier to handle; they may curl up and pucker as you work with them. ​Knit fabrics are not prone to fraying and as such seams do not need to be finished in the same way as a woven fabric, although finishing seams or using an over-locker will provide a more professional and durable finish. 

Knit Fabric Types

Knit fabrics come in different weights, from a lightweight knit to a thicker jumper-style knit.

Cotton Lycra (Knit 180, Knit 220, Knit 260)

Texture: Soft and breathable

Stretch: Our knit has 4 way stretch but not all knit does so be sure to check.

Weights: Cotton lycra comes in three different weights: knit 180 (the thinnest weight), knit 220 (medium weight), knit 260 (the thickest and heaviest weight)

When mixing different weights of cotton lycra, place the heavier fabric that will hold the weight on the top part of the garment and the lighter weight on the bottom

Recommended needle: Knit 180 and 220 Stretch 75/11 Knit 260 stretch 90/14 Or ballpoint 80/12 for all three.

Swim

Texture: Smooth

Stretch:  Swim has 4 way stretch

Weights: 190gsm Floaty and Swishy

Recommended needle: Stretch 75/11 or ballpoint 80/12

Double Brushed Poly

Texture: Looks smooth like cotton lycra, but feels fuzzy, soft and brushed

Stretch: Double brushed poly has four-way stretch with an excellent recovery time

Recommended needle: Ball Point 80/12 or Stretch 75/11

French Terry

Texture: Soft, snuggly and ideal for winter, with a smooth face and soft, looped back

Stretch: Our French Terry has 4 way stretch but not all does so be sure to check.

Recommended needle: ​Ball Point 80/12 or Stretch 90/14

Sports Performance

Texture: Thick​er hand feel, with a smooth satin texture and slight sheen to the right side. 

​Stretch: Sports Performance has excellent 4 way stretch with great recovery, a tighter stretch than Cotton Lycra and Swim. 

Recommended needle: 75/11 or 90/40 stretch needle

Bamboo Spandex 

Texture: Smooth texture similar to cotton lycra, with a luxurious silky hand feel, soft and drapey

Stretch: Four way stretch with good recovery, can grow throughout the day during wear clear elastic in shoulder and waist seams is recommended for heavier garments. 

Recommended needle: Ball Point 80/12 or Stretch 75/11

Tips For Sewing With Knit Fabric

#1 Always Consider Stretch

When cutting out a knit using a pattern, always note the direction the fabric stretches most. The direction of most stretch will need to go around the body, not up and down. Your pattern pieces should indicate the correct stretch direction. Line up the pattern piece parallel to the stretch direction carefully before you cut the fabric.

#2 Pre Wash Your Knit Fabric

Knits can shrink during the first wash, so it’s best to always pre-wash your fabric before you cut out a pattern. Pre-washing will shrink your garment to make sure it stays the size you need in future washes.

#3 Use The Right Pins and Clips

Before you begin, you’ll need to pin your fabric pieces together. For knits, we recommend using a combination of ballpoint pins and Wonder Clips, instead of regular straight pins. Ballpoint pins have a rounder point that slips between the knit loops and keeps the fibres intact, while Wonder Clips prevent you from damaging your fabric on the outer edge of the fabric.

#4 Use The Right Thread and Stitch

Knit garments are made to stretch and fit over the body — and this means the seams must also stretch to fit. To prevent your thread from snapping, we recommend using a polyester thread with a stitch that will expand with the fabric. Most sewing machines come pre-programmed with one or more stitches made especially for knits. These are called stretch stitches. Look in your sewing machine manual to find out which one is best to use for heavier and lighter weight knits. If you do not have a specific stretch stitch, you can set your machine to sew a long, narrow zigzag stitch, a triple straight stitch or a triple zigzag stitch. Alternatively, you can use an overlock machine (also known as a serger) that are perfect for knits.

How To Sew Knit Fabric Without Puckering

Beginning sewers will often find with knit fabrics, their seams pucker up and look wavy. This issue most often occurs when sewing perpendicular to the grain. Puckering can happen anywhere: on the shoulder seams, on the arm curves, around the neck or near the hem. Here are some tips on how to sew knit fabric without puckering.

It is important you do not stretch the fabric while sewing.  Allow your machine to guide the fabric through the feed dogs. Pulling on your fabric will result in gathered and uneven seams. If necessary to start a few cm from the edge of your seam and continue sewing to avoid your fabric being sucked into the machine or puckering. 

#1 Use A Walking Foot

A walking foot adds helps your knit fabric move under the sewing needle evenly with less stretching.

#2 Use A Twin Needle

Twin needles produce a neat, professional-looking seam that stretches nicely, making them the perfect choice for sewing with knit fabrics. This style of needle features two points and eyes, allowing it to work with two top threads at once. On your sewing machine, the bobbin thread is pulled between these two top threads, creating a zig zag pattern under the fabric.

#3 Use Knit Stay Tape

Knit stay tape is super useful for helping you keep your knit fabric in place. Featuring a lightweight iron-on adhesive on one side, the stay tape is stretchy so it naturally adjusts to the stretch of your knit. Attaching stay tape to the hem of a knit fabric garment will help it keep its shape when you hem it up. 

#4 Press With An Iron

When sewing knits, an iron is your best friend because a good steam press will flatten out most wavy seams. To press your seams correctly, lay your knit fabric on an ironing surface, lift your iron straight up, and gently press it down again on the next section of the seam. Do not move your iron back and forth over your knit fabric and leave the garment in place until the fabric cools for a crisp result. 

How To Hem Knit Fabric By Hand

Would you like to hem your knit fabric by hand? Hemming knit fabrics can be tricky since you the opening you create needs to be stretchy enough to pull the garment on and off the body with ease. Here are three simple steps to hand sewing knit fabric:

1. Secure your thread to the knit fabric. Then insert the needle from right to left through a few threads of the garment.

2. You will be working from left to right for this stitch. Moving to the right, insert the thread from right to left through a few threads of the hem. Loosely pull the thread to make the stitching is secure, but don’t pull it so tight that it warps the fabric or prevents the fabric from stretching.

3. Repeat these steps until the hem is secure. More of a visual learner? This helpful video by Sewing Report shows you how to hand sew knit fabric.