Sewing with knit fabrics can be both a rewarding and challenging experience. Although sewing with knits can be a little intimidating for beginners, their stretch and flexibility offer unique benefits, which makes the effort so worthwhile. However, these fabrics also require special techniques and tools. So, to give you confidence, here’s a comprehensive guide to help you navigate sewing with knit fabrics like a pro.
Understand the characteristics of knit fabric:
Before you start sewing, it's important to understand the unique characteristics of knit fabric. Unlike woven fabrics, knits stretch, which can make them more challenging to work with. They come in different types, such as jersey, interlock, and rib knit, each with its own stretch factor and best uses. Spend some time getting to know the different types of knits and their properties, covered further below.
Needles and Thread to Use
Needles
When sewing knit fabrics, one of the biggest challenges is preventing the fabric from puckering or skipping stitches. The type of needle you use is therefore crucial:
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Ballpoint or Stretch Needle: These needles have rounded tips that slide between the fibres of the fabric instead of piercing them, which prevents snags and runs. A ballpoint needle is ideal for most knits, while a stretch needle is perfect for highly elastic fabrics like spandex.
- Twin or Double Ballpoint Needles: These are used for hemming and provide a professional finish with two parallel rows of stitching on the top and a zig-zag on the back, allowing for stretch.
Thread
Choosing the right thread ensures your seams are durable and flexible:
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Polyester Thread: This is generally recommended for knit fabrics due to its strength and slight stretch. It moves with the fabric without breaking but you have to use a zig zag stitch on knit fabrics with polyester thread.
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Cotton Thread: While not as strong or flexible as polyester, cotton thread can be used for lighter knits if a softer finish is desired but again you do need to use a zig zag stitch.
- Maraflex Thread: This thread is made from 100% Polybutylene Terephthalate and has its own elasticity so you can sew a straight stitch on jersey fabrics with Maraflex rather than a zig zag stitch.
Sewing Machine Accessories and Settings
Serger or Overlocker
A serger (or overlocker) is a great investment for sewing, especially with knits. It trims the fabric edge and encases it in thread at the same time, creating strong, flexible seams. It also prevents fraying and gives a professional finish.
Walking Foot or Dual Feed Foot Attachment
These attachments help to feed both layers of fabric evenly through the machine, preventing stretching and shifting. A walking foot is particularly useful for thicker knits.
Preparing Your Knit Fabric
Pre-wash
Always pre-wash knit fabrics to account for shrinkage. Knits can shrink differently to woven fabrics, so this step is essential to ensure your finished garment fits as intended.
Pinning
Use fine or rounded pins to avoid creating holes in the fabric. Alternatively, you can use fabric clips which do not pierce the fabric.
Cutting Tips
Use a rotary cutter for clean, precise cuts. Ensure your fabric is laid flat and use weights to keep it in place. Cut on a single layer, if possible, to avoid shifting.
Stitches to Use and Stitch Length
Zig-Zag Stitch
You need to use a zig-zag stitch on knits if you aren’t using a Maraflex thread. It is perfect for seams on knit fabrics because it allows for stretch. Adjust the width and length to suit your fabric—typically, a medium width and length work well.
Using an Overlocker
An overlocker is ideal for creating durable, stretchy seams. If you don’t have one, a zig-zag stitch or a stretch stitch on your regular machine can work well.
Sewing with Thicker Knit Fabrics like Double Jersey or Ponte
For thicker knits, use a slightly longer stitch length to accommodate the extra bulk. Ensure your machine settings are adjusted to handle thicker layers and consider using a walking foot to keep the fabric layers feeding evenly.
Finishing Hems and Seams on Knit Garments
Use a twin needle to hem knit garments for a professional look. For seams, as mentioned earlier, an overlocker is ideal, but a zig-zag stitch or stretch stitch can also work. Press seams with a steam iron for a crisp finish but use a pressing cloth to avoid shiny marks on your fabric.
Tips for Sewing Knit Fabrics
- Test on Scraps: Always test your stitch settings on a scrap of your fabric before sewing the actual garment.
- Start with simple projects like scarves or headbands before moving on to more complex garments.
- Do Not Stretch the Fabric as You Sew: Let the machine feed the fabric naturally to avoid stretching and distorting.
- Support the Weight of the Fabric: Ensure the fabric is supported as it feeds through the machine to prevent it from pulling and stretching.
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How to Rectify Mistakes: If you need to unpick stitches, do so carefully to avoid damaging the fabric. Use a seam ripper and go slowly.
Types of Knit Fabric
Jazzy Floral Jersey Knit Fabrics
Popular Knit Fabrics
- Cotton Jersey: Soft and breathable, ideal for t-shirts and casual wear.
- Bamboo Jersey: Similar to cotton jersey but with added softness and drape.
- Ponte or Ponte Roma: A thick, stable knit, perfect for structured garments like blazers and skirts.
- Sweatshirt: A medium to heavy-weight knit, great for sweatshirts and joggers.
- Polar Fleece: Warm and cosy, excellent for outerwear.
- Viscose Double Knit: Soft with a good drape, suitable for dresses and tops.
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Ribbing: Used for cuffs and collars due to its elasticity.
Choosing the Right Knit Fabric
- Pattern Requirements: Choose a fabric that matches the pattern’s recommendations regarding weight and stretch.
- Desired Outcome: For a clingy, drapey dress, choose a thinner knit like bamboo jersey. For a structured garment, go for a thicker knit like ponte.
- Stretch Factor: Determine if you need a fabric with two-way (stretches in one direction) or four-way stretch (stretches in both directions) based on the garment’s fit and flexibility needs.
With the right tools, techniques, and a little practice, you can create beautiful, comfortable, and professional-looking garments. By following these tips and techniques, you’ll be well on your way to mastering the art of sewing with knit fabrics. Just look at some of the amazing FG community creations on our socials for inspiration!
