Be sure to read my updated Hemming Tips here.
Sew Mama Sew is putting together a list of SMS Readers’ Favorite Sewing Tips so I thought now would be a great time to share some of the things I’ve learned about hemming knit fabrics. I love sewing with knit fabrics, and most of my patterns are designed to be sewn with cotton or cotton/polyester blend knits. Because of the stretchy nature of knits, sewing them requires a different approach than sewing wovens, but with the right tools, you can get great results. With the wrong tools, you might end up with wavy stretched out hems like this:
My method is definitely not the only method, but it’s what works best for me. I start with my iron and a can of spray starch.
I like to fold the hem up twice. I feel that the little extra thickness gives a nice look to the stitching and it helps keep stretching to a minimum. Spray the hem allowance on your fabric lightly with spray starch, fold up once and press, then fold up again and press. The starch will also help minimize stretching, and it washes right out when your project is completed. I prefer not to pin because I’ve found that pinning tends to stretch the fabric while you’re sewing. (There’s definitely a theme here. The less stretching, the nicer your hem will look.)
Many sewists use a twin needle for hemming knits. A twin needle is a great option because the way a twin needle stitches allows the fabric to stretch without the threads breaking. Unfortunately, I can never get the stitching on the back of the fabric to look nice with a twin needle, and I prefer to stitch along the hem on the inside. I’ve found that another great way to keep your stitches from breaking with stretching of the fabric is to put Woolly Nylon in the bobbin on your sewing machine.
The last, but maybe the most important, tool for hemming knits is a walking foot. A walking foot has built in feed dogs that move the top of the fabric at the same time and rate of speed as the feed dogs on the sewing machine move the bottom of the fabric. This makes a huge difference in how much your fabric stretches as it travels through your machine.
With Woolly Nylon in your bobbin and your walking foot attached to your machine, position your fabric in your machine with the wrong side facing you. Line your needle up close to the top edge of your hem and stitch all the way down. I check to see which guideline on my machine the bottom edge of the hem is on when I first start and then keep the bottom edge right against that line as I stitch. This way, your hem will be nice and straight on the right side of the fabric.
One other thing that you may have noticed is that I like to hem before I sew or serge my pieces together. It’s much easier to hem a flat piece of fabric and keep it from stretching than it is to sew over seams once the sewn item has been put together. I just tie off my serging or backstitch at the end of each seam when the item that I’m sewing is completed.
I hope that helps make sewing knits a little less intimidating. If you have any questions, just leave a comment, and I’ll try to answer them as quickly as I can!
Updating with some answers to your questions:
Tina asked, “Are walking foots relatively inexpensive?” My Kenmore actually came with a walking foot, so I wasn’t exactly sure how expensive they are. I did a couple of quick Google searches, and it looks like the average cost is around $25.
Steph T. and Sarah H. suggested using a ball point needle which is a very important tip that I left out.
Alisa asked, “You just use a regular straight stitch?” and “When you wind the woolly nylon onto the bobbin do you just do it the way you would normally wind it? You don’t have to change tension or anything?” Yes, I just use a regular straight stitch with WN in the bobbin, and I no longer have any problems with the threads breaking. I wind the WN in the bobbin almost the same way that I would wind normal thread. I place the cone of WN in a coffee cup off to the side of my machine and pull it up through the tension disk. Then I tie a piece of regular thread to the end of the WN and use it to pull the end through the hole in the bobbin and wind it up as usual.
the4rs asked, “Do they make walking feet for older machines, mine Elna is from 1960’s?” My trusty Google search found that Sewing Supply Warehouse carries a universal walking foot. You just have to know whether your machine has a low, high or slant shank.
I hope those answers help. Keep the questions coming, and I’ll keep answering!
That was an awesome tutorial. Thanks! I’ve always been afraid to sew on knits because of the stretching, etc. You make it look so easy.
Are walking foots relatively inexpensive?
This is a great tutorial!! I would also recommend a jersey ball point needle for knits. I’m going to try hemming my items before I sew them next time. 🙂 I’m so glad you gave me permission to.
Thank you for the helpful hints! My kids love wearing knits, so I’m sewing them more but never with results this nice 🙂 I plan to pick up some spray starch my next trip to town and pull out my walking foot. It had never occurred to me to use it for clothing! Thanks again for sharing.
Great info. Thanks so much. I have to say that I just ADORE that monstery fabric. It’s super cute.
I just added your blog to my faves after stopping by for the SMS give-away, and lucky I did, because that tutorial is exactly what I needed.
I’ve just cut fabric for at top for myself nad have been dreading the hems, but that starch trick is exactly what I need. Thank you!
Wonderful Bonnie! Thank you! I need to pull out my walking foot and use it. I’ve had it for a year & never used it! I also recommend ball point needles!
Thank you so much! I’ve made some of the cutest T-shirts for DS but I’m never happy with the hem. I hem with wooly nylon in the bobbin before sewing the side seams but never thought about a walking foot or spray starch. I can’t wait to try this on the next few shirts in my “to do” stack. 🙂
Thanks so much for this!
I do have a couple questions…
You just use a regular straight stitch? Having the woolly nylon in the bobbin makes it stretchy enough? (I have had problems with the thread just breaking when my kids put the shirt on so I’ve been using the stretch stitch even for the hem, but it doesn’t look really nice.)
When you wind the woolly nylon onto the bobbin do you just do it the way you would normally wind it? You don’t have to change tension or anything?
Thanks!
Alisa
Great tips, I don’t think I have ever tried wooly nylon, it is languishing in my serger thread box. Do they make walking feet for older machines, mine Elna is from 1960’s?
Love your tips!!!!
These are the best tips I’ve read in a long time. Thank you! I want to sew knits all the time, and have a sewing room full of them, but my projects are never successful. Thanks again!
Thank you, thank you, thank you for posting this! I love your patterns but have struggled with hems. I can’t wait to try out these tips. Hmmm… maybe I can squeeze a shirt in tomorrow 😉
Thanks for this tip. I’ve had 2 cones of wooly nylons for quite some time (buying error) now but didn’t know what to use it for. Now, I know how to use it!
Where do you get your cute knits? That Ooga Booga stuff at the top is adorable!
Great tutorial! Thank you!
What is wooly nylon and where can I purchase it?
I was just curious why you use a regular stitch rather than a stretch straight stitch?
I am going to TRY the WN tip for the straight sewing – but I have a cover-hem machine that I use too – but the problem I am experiencing most is skipped stitches. Even while I am using a “ball point” needle………Any suggestions? My machine is newly tuned up, too. Even if I use a stretch stitch (which is 2 stitches forward, one stitch back…) I just can’t seemt o get it right. It’s aggravating me to NO END.
Sam
Why do my machine-stitched hems on cotton knits turn up (to the outside)? The same thing happens on a lot of commercially produced t-shirts.
Barbara
loved your tips, I found your blog by chance from googling “sewing knits with wooly nylon” now I’ll save the location and come back for more 😉
Thank you for publishing this technique! Just used it to hem a pair of cotton knit shorts and it worked great!
This is a great tutorial. I have been sewing forever, learnt from my grandma. But of course fabrics and techniques (and sewing machines) I also hated that wiggly line when sewing stretch so have oft times avoided it. Many thanks for your tutorial I will visit again and again and ……… (gotta love the internet!!)
What about doing this by hand? I have a polo I would like to shorten as I’ve done with a few pairs of pants, but I have no sewing machine. So far the thread seems to weigh down the fabric so that a line appears on the outside of the shirt. Double-folding might help but might also make the line more obvious. The fabric is a cotton/poly/spandex(5%) blend.
Your articles are extremely helpful to me. May I ask for more information?