Many people think that sewing knits means you need a serger or face disaster. Sure, popped stitches, stretched fabric, wonky seams, CAN happen when you sew knits on a sewing machine....IF you're treating them like woven fabric and just straight stitching. There's a reason sewing machines come with many different stitches. Now it's time to start using them!
Sewing Machine Stitches for Knits
The key is to use stitches that are designed for knits. Over the past few years I've discovered and shared various stitches, but thought it would be handy to put it all together here for an easy "buffet" of knit stitching options. Frustration-free and not requiring a serger!
Triple stitch looks almost identical to a single stitch, except it does each stitch three times (think triple backstitching).
It's meant for projects that require strength & elasticity and eliminates puckering on knits. Ideal for a knit fabric/elastic or knit/woven combo and for heavily stretched seams like neck & arm holes and seats of pants. It's my go-to stitch for most interlock, stretch velour, jersey & sweater knit projects.
This stitch is also great for doing appliqué on knits (find my how-to here). I've noticed factory made appliqué use stitching like this and that explains why those tend to last longer & look nicer than a lot of DIY versions. It also gives a thicker outline than just regular single stitching - especially if you're using a contrasting colored thread.
It looks like this on most machines (even though it makes overlapping rows, not side-by-side):
Triple Zig-zag has three stitches per zig or zag. By setting it to a wide, long stitch (5.0 wide by 2.0 long), it pairs well with elastic trims like FOE (Fold Over Elastic). Great for finishing cuffs, necklines or leg openings that will get pulled on. This is frequently used on items like underwear or cloth diapers.
Obviously this stitch is wide and less "commercial" looking, so it is best used for edging or topstitching knits.
It looks like this on most machines (and is also sometimes offered as a double):
Overcasting or Knit Stitch
Different manuals call this stitch different things, but it works the same way. It's especially flexible, so it works ideally for joining stretch fabrics - especially those with 4-way stretch like velour or spandex or swimsuit fabric.
Just sew with a decent sized seam allowance (like the usual 5/8 inch used in most patterns) and then to trim down the seam allowance with shears when done - careful not to clip the stitching. Or use an overcasting foot and have it overlap the raw edge.
I made my daughter a rash guard/bloomer sunsuit using this stitch. She's worn it every week for swim class for over a year now and it's been pulled & stretched countless times, yet it still looks great, so this stitch is a real powerhouse.
For hemming knits my go-to stitch is really a go-to needle. Twin needles are just what they're called, a single shank that has two actual needles that stitch two rows of stitches parallel to one another. It's fast, precise and easy.
And like the aforementioned stitches, most basic sewing machines can accommodate a twin needle. Both my Janome HD1000 and Brother SE400 machines came with twin needles and have simple set-ups for threading two spools.
My Janome literally involves no extra steps other than looping the threads on opposite sides before threading the needles and no special stitch selection. It's that easy! While using a basic straight stitch for two perfect rows of stitching on the top side,
the reverse side is "knitting" the threads together in a zig-zag for more stretch. Ideally you want it to be very close to the edge, but since knits don't fray, there's no worry of unraveling so I leave a little room just so I'm sure not to miss and end up with a gap anywhere in my hem. It's also totally ok to leave that raw edge exposed (or just trim it down with shears when done). So much easier than double folding a hem and much less bulky too. It also gives a nice professional looking finish to sleeve, shirt and skirt hems.
One thing I have learned is that the wider the space between the needles, the more likely the fabric can tunnel or appear to have a bump between the rows. Adjusting the thread tension can help with that or to use a narrow twin needle on some fabrics.
Many machines offer other stitches that are ideal for knits too. Usually under names like overcasting, stretch, feather, etc. It's definitely worth taking a few minutes to check out your machine's manual to see all its stitch options, recommended uses and then trying them out on a few scraps to see what works best for you. You may discover fabulous, knit-friendly stitches you didn't realize you already had!
Nylon Bobbin Thread
I also find using nylon thread in the bobbin adds a little extra stretchability for seams that will be pulled a lot (like neck holes). The trick is to hand wind it so the pliable thread isn't fully stretched taut on the bobbin. It works like a charm!
Another other item I started using with knits is a walking foot. Most machines don't come with them, so it's an accessory you buy separately. It can be very handy with knits since it grips fabric from the top (instead of just the feed dogs underneath), so the even hold keeps layers from creeping or stretching while you sew. I'd done a fair share of knit sewing without it that worked out fine, but I think it really makes a difference with thick or slippery thin knits. It's also great for quilting, heavy weight and fabrics like laminate or silky synthetics that can easily shift, so it's worth having in your supply box.
A word about sergers
I do want to say that I'm not hating on sergers. They can be an ideal way to finish knits or fabrics that easily fray and offer the ability to sew with 3 or 4 threads at a time. They just require added expense (about the cost of a 2nd machine) and there's a bit of a learning curve to use them.
My husband bought me one a while back, but the manual & instructional dvd that came with it were less than stellar (I fell asleep watching the dvd - it was that bad). Poor instructions and tricky threading seem to be common challenges, but there are a lot more how-to's & serger classes out there to make it easier. While it's been a lot quicker for me to just use the stitches above, figuring out my serger is on my 2014 summer to-learn list. And of course I'll share my findings here when I do:)
So now that you've got the info, grab some knits and your sewing machine & give them a try!