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Sewing with knits

SEWING JERSEY TIPS

Sewing a knit garment can sometimes seem a bit daunting. Many makers think you need specialised machinery, but really good results can be achieved on an ordinary domestic machine. The trick is to test your machine stitch and tension settings before you start and make sure you use the correct needle to avoid skipped stitches.

UNDERPRESSING

My one major piece of advice I would like to offer, and this applies to ALL of your makes, is to take your time and underpress at each stage of construction. Underpressing just means that you will press as you go and press each seam after sewing it. I tend to sew everything I can in one hit and then move on to press everything I can while I’m at the ironing board. I apply the same principle to neatening my seams at the overlocker. I was taught by the sample machinists I worked with to first press the seam flat so the stitches are set into the fabric, and then either press the seam allowance open or to one side. This does give a more professional finish and even though you are effectively pressing each seam twice, pressing the seam allowance flat and together first makes it much easier and quicker to press open or to one side. And do remember that pressing is just that, lift your iron and use it in an up and down motion, not a dragging side to side motion. And be gentle!

  • Always use a ballpoint, jersey or stretch (usually recommended for Lycra) needle so you don’t get skipped stitches.
  • Use a stretch or ballpoint twin needle to create a faux coverstitch for the hem.
  • Don’t pull and stretch your fabric as you sew, though I find holding it firmly to create a bit of tension as it is stitched can be helpful.
  • If your seam goes a bit wavy after stitching, very gently steam and press flat.
  • I have used a walking foot in the past, which helped but I don’t think it was essential. It would be worth trying if you have one, but they can be expensive to buy.
  • My machine tried to swallow the garment into the footplate at the beginning of a seam, so I placed a piece of paper under the garment before stitching. I had some heavy tissue paper handy but the off-cuts from printed Indie sewing patterns would be perfect!
  • Not sure which needle to use – here’s a link to a handy chart.

THREAD

  • You’ll want to sew with a polyester thread as it is stronger and has more ‘give’ than cotton thread so will stretch with the garment and is less likely to snap.
  • UPDATE: I haven’t tried it yet but there is now a thread specifically designed by Gütermann for sewing stretch fabrics. The Gütermann Maraflex Thread is a high stretch thread with a seam stretch of up to 80% and designed so you can stitch jersey with a straight stitch on an ordinary domestic machine.

STITCHES

The Somerset T-shirt Stitch Chart | Maven Patterns
The Stitch Chart

Create a Stitch Library | Test your stitches on a scrap bit of fabric first. Stitch in both directions, along the selvedge and across the width of the knit, to make sure your stitches don’t crack when you pull them. Record your machine settings on the Stitch Chart included in the Somerset T-shirt pattern, or in a notebook, to create your own Stitch Library so you can refer back to them easily during the construction of this (and future!) garments.

Tension and stitch settings will vary and be dependant on your machine and your fabric. The best method, tension and stitch length settings will vary depending on your sewing machine, the fabric you are using and the finish you prefer.

There are a couple of different options (listed below) for stitching your seams. You really need to get friendly with your sewing machine manual and you may find further guidance there on selecting a suitable stretch stitch as your machine may have different stitch options available than those we have listed. I can’t state this enough…test them out on a scrap and see which one you prefer and works best for you and your fabric.

Zig-zag stitch | lightning stitch | straight stitch | 4 thread overlocker
  • Zig zag on a narrow to medium width and 2.5-3mm short length (I used this as was quicker than the lightning stitch, and set my stitch width to 0.5 and stitch length to 2). Don’t stretch the fabric as you stitch, just guide it through the machine and let the feed dogs do their job.
  • Stretch stitch (sometimes called lightning stitch). This is a specific stretch stitch which preforms well. The disadvantages are it is slower to stitch a seam with and it is harder to unpick than the zig zag stitch. Again, don’t stretch the fabric as you sew.
  • Straight stitch. This one may be controversial but I actually stitched mine with a straight stitch, and just pulled the fabric very slightly in front of the needle so it was under tension as it was stitched but I was very careful not to stretch my seams. My t-shirt has been heavily worn and washed and the seams haven’t cracked to date. Keep in mind what type of garment you are making and what type of knit you are using. Do not use this if you are sewing a very stretchy jersey or making activewear or swimwear though, I haven’t tried it but I’m pretty sure your seams will crack under those circumstances.
  • Overlocker – you can cut, sew and neaten your seams all in one go. 3 threads are usually just used for neatening seams, 4 (or 5) threads are used for all in one seam stitching as it makes for a stronger seam. The stitches have a built-in stretch to them.
  • Neaten seams. To neaten your seams either use a zig-zag or overlock together. You could in theory just stitch and leave the edges raw and unfinished or trim them with pinking shears as knit fabric don’t really fray.

CUTTING

  • Prewash and press
  • Lay the fabric flat on the table, do not stretch it but let it relax.
  • It’s preferable to cut knit fabrics in a single layer for accuracy.
  • If folded make sure the underneath layer is flat too as it has a tendency to ‘ripple’ as it grabs the top layer.
  • Do not let it hang off the edge of the table as it will stretch the cloth out of shape or pull it off-grain.
  • Pin in the seam allowances to prevent marking the body of your garment.
  • Or use weights and cut with a rotary cutter.
  • INDUSTRY TIP | mark the wrong side of the fabric with a chalk cross it if isn’t easy to spot the right and wrong side. Black jersey – I’m looking at you!

Other Somerset T-shirt tutorials | How to Twin Needle | The Somerset t-shirt