Muscular Monday: The 4-Way-Stretch Sewing Experiment

Happy New Week, everyone! (Sounds more festive than "Monday" - don't you think??)

Last week I shared with you my newest athletic sew obsession - The Greenstyle Stride Athletic Tights. And while you all overwhelmingly responded with great interest for the design (and why wouldn't you??) - I also heard a lot of fear-of-sewing the athletic fabrics the pattern calls for.  That's reasonable - 4 way stretch fabrics are notoriously shifty! And you may have heard a lot of advice as far as what tools work best for sewing with knits. So I decided to round up my knit-sew materials, and set up my own little comparative review. Which will work best?? The links to all products in this experiment are affiliate links. They're meant to be informative - so you can see price and descriptions - but if you do happen to purchase any of these tools, I'll get a small commission on those sales. Thanks for supporting my blogging habit!

Now, it's been a while since I've had a science class, but from what I remember, a true experiment needs a set of constants, and only ONE variable. So let's talk about those now. My constants are:

The Stitch:
I'm using my Brother SE 400 which has quite a few stretch-stitch options. But since some of you will be sewing on simpler machines, I'll choose one most people should have access to: the zig zag stitch. Specifically, a narrow zig-zag (1.0mm wide). (How does this work for stretch fabrics? There's enough extra thread in each seam to stretch where needed!)

I chose a standard stitch length of 2.5mm, though for topstitching I use 3.5mm or even 4mm.

The Tension: 
For wovens, I use a medium tension - about 5. But knits need seams that are a little more forgiving, so I lower my tension. For this experiment, I'll be using between a 3 and a 4 tension.

The Thread:
For both my upper and bobbin, I'll be using my Aurifil "elements" collection of 100% cotton thread. I chose this for no other reason than it's easy to see in pictures! Plus, it's Kate Spain's collection, so you know those colors are purdy, too :) 

If this were a real sew, I'd be using woolly nylon in the bobbin. I find this holds up better to seam-stretching than the standard cotton thread.

The Needle:
For all the stitches in this post, I'll be using a brand new microtex needle. (Or "Sharp" needle) They dull quickly, so expect to use a new one for each project. Load up on these puppies when they're on sale!

The Fabric:
4-way Stretch Nylon Lycra from Cali Fabrics. Each stitch will be along the greatest stretch (selvage to selvage). This way, if any of the presser feet don't allow the fabric to pull through easily, you will see how much the fabric stretches along the seam.

I will be using 2-by-10 inch scraps of this fabric, and sewing down the middle. To mimic a real project, each example will sew through TWO pieces of this fabric. I'll also eliminate the chance of the fabric being sucked into the machine by starting my seam 1 inch from the raw edge.  


The Control:
My "control" for this experiment will be the standard presser foot. This is the presser foot that comes with your machine, and that you use for a majority of your sewing projects. 

The Variables:
I will then repeat the experiment with two other presser feet: my walking foot, and my teflon foot.


Let's see how it works out!

First up, the mini zig zag down the center. I did NOT pull or guide the fabric in any way. I wanted the results to show if there was any feed issues as a result of the presser feet:

  • The far left here, sewn with the standard presser foot, ended up having trouble pulling top and bottom fabrics evenly. The top layer didn't slide as easily under the foot. 
  • The teflon foot worked best of the three. 
  • The walking foot kept top and bottom layers together well, but did not feed evenly right vs left, and veered dramatically off course.
  • All three feet created a "bacon" strip effect, warping the fabric. My best guess is an even lower tension would have worked best, but also that the two presser feet that had the hardest time sewing straight (original presser foot and the walking foot) were stretching the fabric as they sewed:

The walking foot sample was the only one with skipped stitches:

Next up is the top stitch. I flipped the top layer of fabric across the line of stitching so I'd be sewing through 3 layers of fabric this time. I did assist the fabric through on this step. And I lengthened the stitch length  and width:

Once again, the only skipped stitches are with the walking foot, and the best sewing experience was with the teflon foot. You can't see in this in a photo, but I had to do a considerable amount of fabric-feed-adjusting to get a neat topstitch on the standard presser foot. It yields the same results, but it's more mentally taxing.

BONUS: What about the twin needle?? Twin needles add a professional finish to topstitches and hems on any project, and they also allow for STRETCH on knit fabrics! So I grabbed my stretch twin needle, a narrow one to minimize the "tunneling" potential, and adjusted my settings. (You DON'T zig zag with a twin needle!)

I was in no way surprised to see the skipped stitches on the walking foot sample again, but I was surprised to see some for the first time on the standard presser foot, too. The winner, by far, is the teflon foot:


For those who sew with 4-way knits - do you find this experiment consistent with your own experiences? What other tools would you like to see tested? Let me know your thoughts below!

UPDATED TO ADD: Maria, one of the many brainy folk in the Capsule Wardrobe Sewalong group expanding my sewing knowledge, suggests a roller foot, too. I don't have one to experiment, but I like the promise that it's "effective for preventing fabric (stretchy materials like jerseys and knitted fabrics or hard-to-feed materials like leather or vinyl) from slipping or puckering." I may just have to try it out!