Understitching: A Step-By-Step Demo

Here’s another post for the beginners or semi-beginners out there – all about understitching! I was understitching the facings on the Picnic Dress and paused to take a few photos and write up this quick post.

What is understitching?

  • It’s a row of stitching, usually seen on the inside edge of a facing, that is there to help keep the seam rolled to the inside of the garment.
  • Understitching is never visible from the right side of the garment
  • Understitching stays in permanently, unlike basting
  • Understitching seems like a step you could skip, but you shouldn’t!

Here’s how to understitch your facing:

First, grade your seam allowances. (This helps reduce the bulk of your facing seamline!) Trim both seam allowance, reducing them to half of the original allowance. Now, trim the facing seam allowance in half again.

Clip inner curves so the seam will lie flat, by making snips into the seam allowance, about 1/2″ apart. Make more snips into very curved areas, less snips into less curved areas. Be careful not to snip into your stitching line!

See, here is our clipped seam allowance:And here is the clipped seam allowance, look how the curve can now be stretched into a straight line! This is an important step, otherwise it will be harder to understitch the facing.Now that we’ve prepared the seam for understitching, let’s do it! Take your piece to the sewing machine.

Arrange your piece so that the facing is on top:Now, open up the seamline and stretch the seam as much as you can (gently!) with your fingers. You’ll notice we didn’t press the seam open with an iron. I find you get better results by stretching and understitching, and then pressing the facing. This way there’s no crease-mark when you understitch.Now, insert the needle into the facing, very close to the seamline. You want to keep this stitching very close to the edge, as close as you can maintain, while not crossing over onto the bodice front fabric. If you can manage at least 1/8″ that will work.Lower your presser foot. Begin stitching slowly, stretching the seam open with your fingers as you go.

My fingers look really awkward in this photo, but that’s because I’m taking the photo with my right hand. It’s much easier if you use two hands, one on each side of the facing seam to pull it open!Continue along the seamline until you get to the end. Backstitch and trim threads.

Now, look at your facing. Look how nicely it rolls to the inside of your garment! We’ve made it want to stay put in the right place. Now pressing the facing is so easy, since we’ve created this lovely natural curve.So that’s all there is to it! Press your facing into place and admire how nice and tidy the edge is. (Isn’t this fabric delightfully girly and pretty, too?)

Next up: handpicking the zipper! There are a number of great tutorials out there already so I will keep mine pretty simple. If you’re dying to know how to hand-pick a zipper right now – check out either Gertie’s tutorial or The Cupcake Goddess’s tutorial. Both are excellent references to getting that tidy, hand-picked look!

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32 Responses to Understitching: A Step-By-Step Demo

  1. Emer November 1, 2010 at 6:15 am #

    Thanks for more great tips. I never clipped the seam allowance. Next time I will try this. And the ironing tip is great too.

  2. Stacy November 1, 2010 at 7:35 am #

    Ugh, I really hate understitching. It’s such a pain to me, although I don’t know why. But I’ve skipped it out of laziness before and you’re right, it really shouldn’t be skipped. Thanks for the reminder. :)

  3. Catherine November 1, 2010 at 8:47 am #

    Ok, NOW I get it! Thanks :D

  4. Caroline November 1, 2010 at 9:41 am #

    …Yes, and you have a *really* nice Pfaff! Geez, I wonder how you limit yourself.

  5. ~Sherry~ November 1, 2010 at 10:33 am #

    Excellent tutorial Tasia about a Very Important Thing! Understitching is one of those things that really takes your garment from amateur to professional.
    Dress is looking so pretty!

  6. petite josette November 1, 2010 at 11:11 am #

    Thanks for this tutorial

    I put a neck facing in my latest blouse yesterday and did an understitching, but the result isn’t as neat, the seamline still appears on the sides. I should probably trim the allowances like you recommand, and maybe clip the curves a bit more. I’ll perfect it when I get home tonight !!

  7. The Cupcake Goddess November 1, 2010 at 11:28 am #

    This really is brilliant Tasia! I am a big fan of understitching and usually do it, even if the pattern doesn’t call for it. It really helps that bottom fold to fold under and stay that way. I am loving your sewitionary. It’s going to be a great reference for many stitchers!

  8. A Sewn Wardrobe November 1, 2010 at 12:07 pm #

    I think understitching is one of the most important steps a sewer can make, too. Great tut!

  9. Samina November 1, 2010 at 12:37 pm #

    Thanks for teaching me yet another thing about sewing! There’s so much to learn – do you take boarders?!

  10. LDerriso November 1, 2010 at 2:05 pm #

    This is GREAT! I was reading about this the other day, trying to understand it. Thanks for all the helpful hints.

  11. Alessa November 1, 2010 at 10:46 pm #

    I’ve had some trouble with bulging facings and I’ve always topstitched them until now… this seems so much neater, I really need to try it!

  12. laurel October 27, 2012 at 7:42 am #

    thanks I had never heard of understiching and could not figure out from the directions and picture in the pattern how to do it. Halloween is saved!!!

  13. Shari January 4, 2013 at 8:35 pm #

    Thank you so much for this! I was looking for a tutorial on understitching, and the first one I clicked on made it look so scary! The fear is now gone – and I agree that the professional finish on this is amazing. Thanks again!!

  14. Marijke February 24, 2013 at 1:22 am #

    Thank you so much for this tutorial (and your entire blog, very interesting to read and usefull)! I used it to finish a garnment and it really gives a neat result. I used a fabric that I saw on your blog too (if I’m not mistaken), a Nani Iro double gauze in dark green with flowers (mainly coral), a wonderfull fabric that deserves a nice and tidy finishing.

    ps: A little too late: Happy Birthday!

  15. Carley June 5, 2013 at 4:13 pm #

    Hi Tasia!

    Great tutorial on under stitching! That is exactly how I do it too, trim, grade, clip, understitch, press. I have looked at so many books and pattern instructions, lately, that tell you to press first that I was beginning to doubt myself!



  16. Shanna November 10, 2014 at 5:50 am #

    Thanks for the tips! I do prefer understitching, but I always get confused when understitching a neckline with a collar. What is the correct method for understitching a neckline with a Peter Pan collar?

    • Tasia November 10, 2014 at 9:29 am #

      Hi Shanna! If your collar is finished with a facing on the inside, then simply follow these same steps and ignore the collar. Understitching always goes on the inside edge. If your collar is finished with bias tape, then understitch on the bias tape. If your collar edge is finished with lining, then understitch on the lining. Basically, whichever edge is going to be along the neckline on the INSIDE of the garment, that’s the side you understitch!


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