Finally, finishes for knits that don't look home made

Knits can be trouble. Because they stretch, they want to stretch as they go under your presser foot resulting in puckered, stretched, or lettuce-edged seams and edgings that look horrible at worst and home made at best. Here are some things I've found that help create professional looking finishes.

First of all, if you have a walking foot, use it. My primary machine is a Pfaff 1471 with a built in walking foot, but because this pulls from behind the foot rather that in front, I still had stretching when I sewed. A really good combination is Singer's rubber feed dogs (on older models) with the even feed foot. This has the capacity for extremely precise sewing, especially on difficult fabrics, as long as the machine will tolerate the fabric.

Secondly, make liberal use of laundry starch and let it dry before continuing. This seems to take forever and ironing doesn't speed up the process much. Sometimes spray starch is enough but other times it can be enormously helpful to make up a batch of Argo starch and dip your fabric in it before it is cut. The starch really helps control rolling edges and gives body to unruly lightweights that machines sometimes struggle with. However, my Singer combination described above just would not tolerate the lightweight T shirt knit shown below (this was before I learned about using boiled starch). Fortunately, my primary machine did, but if your machine is struggling there are a few things you can try. The only one I know off the top of my head is to sandwich the fabric between layers of tissue paper. Another thing that might help is to decrease presser foot pressure.

For edgestitching, adjust your needle position so you get as much fabric as possible under the foot. And obviously, you should be using ball point needles. Most knits require a seaming stitch with width, but if a straight stitch is used, it can be advantageous to use the straight stitch foot and throat plate.

Hemlines

I did some internet research for hemming knits and almost every site recommended stitching the hem with a twin needle and woolly nylon in the bobbin. Even Nancy Zieman says to do it this way. The combination of zigzaging and built in stretch of the woolly nylon is supposed to give the seam a lot of stretch. Maybe it's just me, but every time I try to do this, I end up with a tuck between rows of stitching. Even if I manage to stabilize the fabric enough to stay flat during the stitching, as soon as I flex the seam, the tuck appears and won't go away. After lots and lots of experimentation, I came up with a good, flat hem solution for casual garments.

Bottom row is wrong side

This is a feather stitch over the turned up, raw hem accomplished the same way you'd do a cover stitch. The raw edge doesn't need to be finished because knits don't ravel and finishing adds unnecessary bulk. Stabilize the entire hem with spray starch if you didn't dip the fabric before starting your project--from the hem allowance to the stitching line--and press it to the wrong side. Stitch from the right side, placing your line of stitches to catch and cover the raw edge. You can either stitch a fixed width from the edge and cut off any excess later or you can adjust your stitching according to the location of the cut edge if your cutting was precise. You can feel the cut edge under the top layer while you're topstitching so you know where to sew. I figure nobody's going to be looking closely enough at my hem to notice whether the stitching varies by an eight of an inch here and there and it saves me the trouble of doing any trimming later. I was surprised by how good this looks on the finished garment. It lies flat and mimics coverstitching very well.

Before I discovered this, I'd been finishing the edge with serging and zigzagging the hem seam:

You don't need to do this

This just doesn't look as good.

 Another good way to finish an edge when a narrow hem is desired is to do this:

I don't know if you can see this well, but this hem was turned up 5/8" and zigzagged 1/4" from the fold. Then I trimmed off the excess close to the stitching. I expect it to try to roll after it's been cut a while, so I'll come back later and trim again when it does. Again, flat seam that isn't bulky. Update: on this particular fabric, this hem isn't stable and the whole thing rolls.

Here's one I thought was clever at the time:

This is a 3 step ZZ on slippery Under Armour in green thread. I thought the green would look somehow bolder but I'm glad it didn't because the stitching is irregular due to the slipperyness of the fabric. If I'd used white thread it wouldn't have mattered. This whole shirt is kind of a disaster as you'll see below.

If you have a fabric that still won't behave, you can fuse a strip of knit interfacing to the hem allowance before stitching. Steam-a-seam was recommended to me so I went out and bought some. When I used this, the hem was stiff and heavy and had no stretch at all. It made it look like masking tape was stuck to the underside of the fabric. You definitely want to use knit interfacing if you do this.

Necklines

Necklines give me the most grief. Almost any kind of treatment (binding, facing, turning under) comes out stretched or otherwise botched. Ripping stitches out of a knit is a nightmare and I've had to rip out many a neck treatment. My first attempt at making a neckline without ribbing was the under armour shirt mentioned above:

I turned the edge under twice and stitched it, not knowing what was going to happen. I ripped this out and put on foldover elastic but cut it the length of the neck opening circumference. This was even worse. I ripped out again and cut the elastic shorter with no improvement. I ripped it out yet again and let it sit for 9 months. By this point, the neckhole had grown considerably from all the stress.

In the meantime, I learned how to make this from a back issue of Threads:

In the May 2003 issue, there is an article, "Neckline Finishes for Knits," that describes various finishes for knit necklines, including this one. The author also has videos on Threads' website that show you how to do it. I don't know what to call this; it isn't bound and it isn't ribbed, although the process is identical to applying ribbing. The secret is the difference between the binding length and the neckhole circumference. Your binding has to draw in the bodice fabric without gathering it so you have a nice, tight finish. The seam is stitched with a narrow 3 thread overlock so it stretches. This was a breakthrough.

Encouraged, I went back to the under armour with my new technique. Now I have success!

I didn't even bother to change the thread in the machines. I just used what was already there. The shirt was already such a mess, it isn't going to matter. What does matter is that I can do this! And since I learned about this, I've noticed how many of my ready to wear clothes have this finish. Some of them have the seam allowance topstitched, but when I tried to do this, I got another stretched out neckline. I just let them float. They're not going to stay where I want them anyway.

A few hints that are in the video but not the article:

1. Sew the binding to the neckhole with the garment lying flat across the machine bed like this:

so you can sew a curved seam and also see when you need to stretch. She's got the foot inside the neckhole with the shoulders on either side.
2. Stretch in the same areas as you did when determining the length of the binding, i.e. more for sharper curves and less for shallow ones.
3. Don't stretch the bodice while sewing if you can help it.
4. You may need to stretch the seam slightly while serging.
5. Use a wider seam allowance when serging in order to cover the basting stitches. This is where I go wrong a lot. Having an adjustable seam guide on your serger is invaluable.

You can sew a piece of ribbon over the seam allowance to stabilize the back of the neck if it wants to stretch too much.

Here's another method that looks promising. I haven't tried this yet, but it looks like it will work if you can control the stretching as the fabric passes under the foot.