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Creating a Back Neckline Dart for Better Fit

How to add a neckline dart in back

In a moulage (custom bodice sloper) class I taught at Ryliss Bod’s Sewing and Design School in Tacoma, Washington, I had a student who had a broad back and a high curve at the nape of the neck.

Student Ann Long said she was adding a center-back seam to her patterns to accommodate the curve. Since this curve is pronounced, when she sewed garments using that alteration, she got what I call the “shark fin,” a ridge on the seam caused by the curve that is too sharp to fit into one seam. I’d like thank Ann for so kindly allowing me to take photos of her and for using her as a lesson for us. By the way, I’m teaching a few more classes in the Seattle/Tacoma area for Ryliss, as is Susan Khalje. If you’re interested in knowing more about them, you can email Ryliss at: [email protected]

back view of moulage muslin
From the back view, you can see student Ann Long is broad across the back. She’s wearing the muslin of the moulage we drafted using the information below.

side view of the muslin's fit
The contour we needed to fit is clearer from the side view.

In drafting her moulage, Ann had an angle form at the intersection of the shoulder line and armhole that is much greater than it should be. I like an angle somewhere around 90 degrees, or slightly more. The vertical line in the draft that intersects the armhole represents the cross back width. Ann has a broad, strong back, which showed up in this measurement. So, the cross back vertical line is farther from the center line than her shoulder width.


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Previous: Professor King on Fitting the Back Next: Learn How to Fit the Back


  1. Judy G. | | #1

    Kenneth, love all your instructions for their clarity.
    Thanks for sharing them with us.
    Judy G.

  2. Carol_Z | | #2

    This pattern alteration makes a lot of sense to me. Thanks for sharing, KK.

    Carol Z.

  3. buffgal | | #3

    Thank you so much!!! Nice to know I've been doing the right thing for years, however, this is very, very helpful to fine tune my stuff. Silvia

  4. User avater
    LuvThreadsMagazine | | #4

    Senor King does it AGAIN!!!

    They say genius is making the difficult look easy. These instructions took a complex fitting situation and made them understandable.

    That said, one wonders what he could do by focusing on global economics?

  5. Sunshine12 | | #5

    Thanks so much for making the solution to this problem something I can understand. So many times we work hard to make beautiful things for ourselves and others only to have them not fit as well as they could because we don't know the techniques needed to fix problem areas like this, but with the help you provide we're learning to resolve those problems. Thanks!

  6. Mamato8 | | #6

    I have been adjusting store bought shirts that are big enough around, but with shoulders way down by the elbow. I made that first correction, but now I am seeing that a dart would make it all look better.

    Very good tutorial! I want to copy it for my patternmaking book!

    My question: what would you do for a knit shirt? Or a shirt with a yoke? These are uniforms for work or ministry.

  7. Brabant | | #7

    Thank you Kenneth: I thought I was the only one with a broad back and a kind of hump between neck and shoulders. AND I kept wondering why nothing really fitted. I can tell you nothing gets rid of a broad back and even losing weight does not shift the hump!

  8. olifant | | #8


    Thank you so much for the fitting information. We are not all size 0 or 2 and some of us have to adjust patterns. We still want to look fashionable even if our bodies are not perfect. Please bring more. I love it!

  9. adyt | | #9

    I, too, have a broad back and my problem was a gap in the back neckline (sometimes I'd have the problem, other times not), so I have been sewing the seams on each back side at the neckline for years. Sometimes it shows up (ever so slightly but it bothers me!) after I attach the interfacing and the zipper so my solution is to take in the interfacing just as I do the dress. I have to do this because the gap shows up after I have done all the construction and have trimmed the interfacing and dress seam which I am hesitant to completely remove, and the zipper is already attached! So far I have had no bulk at the back neckline, but when I sew with heavier fabrics, like wool, I make sure to check for the potential problem to avoid my last resort measure which can surely give me bulk. I will try your technique on my next dress.

  10. NinaLBoston | | #10

    Thanks, Kenneth, for this wonderful explanation. I wish you had also included a "before" photo so we could see your initial diagnosis.
    Once I was a size 10 petite who needed only to shorten the shoulder seam and widen the hips. Now I need to make many age-related and posture-related changes for a curve at the upper back, lowered bust point, and high curved abdomen. Thanks for addressing these issues in your tutorials. You help me in my quest for a distinctive wardrobe that FITS!
    It is my dream to one day take a live course with you on the East coast. Maybe after my DD graduates college. Oh well, they say a pleasure deferred is that much sweeter.

  11. Belair108 | | #11

    Thank goodness SOMEBODY realizes that even people who are not age 20 and size 2 need clothing too. I have often thought that some designers are missing the boat by not adjusting sizes. Oh they do to some extent - but the results are not flattering. If I go up a size, the hips are way big and the shoulders hang off the sides.

  12. reddevilforlife | | #12

    Ehhh!!..Nice post!!

  13. Dee1380 | | #13

    Wow Thank you so much for this very clear explanation.
    It is so simple, now that I understand!

  14. User avater
    kennethdking | | #14

    Thanks for the kind words! As for global economics, that would be a stretch (I fell asleep many times in Econ class in college), because I can't balance a checkbook. But I do understand geometry.

    As for the "before" photo of the draft, it looks like the first photo in the lessons. As I was just working on instinct, we hadn't made u a muslin yet--this draft she's wearing is the first shot. She gave me a big hug and kiss after we zipped it up, as she'd not ever had a first muslin fit as well before. Good success, and all of Ryliss's students in her school in Tacoma got to see something new.

    (As an aside, Susan Khalje and I are doing a sit and sew in Tacoma for Ryliss in November.)

    To the question of how to approach knits, I'd put the darts in knits as well. There seems to be this idea out there that we always need to eliminate darts, and, wherever one can, then, yes. But darts give shaping, and having darts at the neckline is preferable to gapping--the gapping draws the eye there much more than a dart would.

    As for yokes--an excellent solution for hiding the darts. You'd draft the horizontal yoke style line so it passes right under the points of the darts--separate the yoke piece from the main body, and then just fold closed, and tape the darts. The shaping provided by the neck darts would then be transferred into the seam joining the yoke to the main body, and nobody would be any the wiser.

  15. KayGV | | #15

    Thank you for sharing fitting tips for "real people" of all sizes and shapes. As we baby boomers age, I am convinced that your down to earth explanations and innovative approaches will be in constant demand!

    I suggest that another body type you might illustrate is one which is permanently bent at the hip, as in people who use walkers or crutches for mobility. Trying to make a top that hangs straight without looking huge in the front is a real trick. Furthermore, making a dress with side seams "true" has forever eluded me. Any suggestions, Kenneth?

  16. User avater
    kennethdking | | #16

    Good comments all!

    As for the moulage--sorry I didn't define that.

    A moulage is a draft from the measurements of the figure, that I learned from my teacher Simmin (pronounced Simone). She got her master's degree in haute couture patternmaking at the Ecole Guerre-Lavigne in Paris. The moulage fits like a second skin, and is used in a variety of ways. Firstly, it is how I generate slopers from measurements so I can draft patterns for my customers.

    Since it's drafted with no wearing ease, it can be used to cover a dress form--it is the method I used to get the cover for the article on padding a form to match a figure.

    It also is my foundation draft for strapless garments. Since they need to fit snugly, this is the perfect starting point.

    And as to the question of having side seams true:

    This is a no net change between the front and back at the side. When fitting, I take a straightedge, and draw the seam line plumb with the floor, right where I want it. Take the garment apart, and transfer these marks to the pattern.

    Then, it's a matter of moving the seamline where it deviates from this line, by either taking from the back and adding to the front, or vice versa. I'll do a blog post to explain this--I'm always looking for ideas for posts, and this is a good one. Stay tuned!

  17. MrsHGW | | #17

    I have books on the subject but it never made sense until now. Thank you. If I am right, first you set up your measurements, then you notice where the angles are wrong. (But no one tells us what the angles should be if we do not have a pattern. A mental sum of similar patterns in our heads gives us that sense, but for many of us it has been wrong, and we get frustrated looking for results by adjusting in the wrong places.) Then you note the negative space that needs to be moved and place it where it might look good. (Any good rules for us there?) Then you use tracing paper to see what you are doing as you pivot your work so that the negative space can be transferred to the new location. I am going to try that. Cut and slash always got me lost from where I was to where I should be going. I have lots of shark fins in my work to date and could not quite put my finger on just where I was wrong. Many thanks to your model for being so very helpful to us. And thank you for using colors to guide us. That helped.

  18. User avater
    kennethdking | | #18

    To Mrs. HGW:

    You're on the right track. Good work!

    As for what the angle is, I was going by instinct here. The vertical line on the draft represents the back width, and if you look at the figure here, she's wide all the way up, with strong square shoulders. The angle where the shoulder met the armhole looked too flat to properly reflect this particular figure. So I followed the 'lead" of the vertical back width line to determine the proper angle of intersection. An educated guess.

    Part of figuring this out, is experience: making literally hundreds of these moulages--I can tell by the draft of a measurement went wrong, and in this case, where a special condition exists.

    The "shark fin" as I call it, is an indicator that you're trying to take too much shaping into a seam. Our model had just this problem when altering patterns in that region. I see this also on side seams on skirts where there is an hourglass figure--tiny waist and fuller hips. When I see this, I know that I need to add a dart or two to divide up this shaping so it takes in more gradually.

    In any method of altering a pattern, I strongly recommend marking the stitching lines onto the pattern, and copying the pattern onto white paper--kraft paper, the "project paper" you get at the office supply store, butcher paper--any paper that has body will help you to alter.

    Also, working from stitching lines, and then later adding back the seam allowances, will eliminate confusion in altering. Some try to save time by not doing this, but in the end, get a little lost. As I'm a little dyslexic, I know I have to take the time to do this step before proceeding.

  19. User avater
    kennethdking | | #19

    In regards to design features that will flatter this neckline:

    I recommended to her, that the neck seam not go all the way to the base of the neck--cut it away about 1" from the base of the neck, and then create a standing collar, about 1 1/2" high. Having the collar standing literally in the middle of this curve, will visually make it flatten out by stopping the eye at the collar, not all the way up to the base of the neck.

    She would also look well with the boat neckline cut away from the neck with the little standing collar--it will play up her strong shoulders, frame her face, and direct the eye away from the curve at the base of her neck.

  20. user-2055414 | | #20

    Thank you Kenneth. I manage a costume shop and in one of our shows this season we will be creating a slight humpback for an early 1900s piece. I think this technique may work well for shaping his tailored coat.
    Angela H

  21. User avater
    kennethdking | | #21

    A perfect use for this technique, and one I didn't think of--in costuming! Thanks for the comment--I learned something today! That's one of the many benefits of doing what I do--I get to learn new things frequently. Good stuff.

  22. dreamlady | | #22

    I am working with patterns in the old way the front and the back on the same flat sheet I don't know what is the name of that kind of pattern is it a french way or the italian way or what please help

  23. DrivesSewMachBest | | #23

    I did this, not knowing the art of altering except that what was needed on one side needed to pretty closely follow on the other (based on the model at hand, my daughter.) Your presenentation makes so much sense, after the fact. My daughter has Down Syn and Hypothryroidism and never grew tall to her best potential.

  24. User avater
    graceross | | #24

    So cool! I'll be trying that.

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