Fitting: Sway back on a Colette Laurel (Pt II)

So a little latter than planned,, here’s the second instalment of the sway back adjustment I promised. You can read part one here. But just to recap quickly on where we got to…loadsa fabric in the back for me. Pinned one horizontal tuck….didn’t quite take care of it*. Pinned a second horizontal tuck further down…part one of problem solved… *(worth noting that I have omitted the back darts. This will have had a small impact on how much I had to pin out)colette laurel sway back adjustment

Then with the toile taken apart and pressed flat, I’d marked all my adjustment lines in pen and evened them all out…colette laurel sway back adjustment

Soooo…moving forward, the next step was to make those adjustments to a paper pattern. To do this I laid out my toile back piece and laid some swedish tracing paper on the top. Making sure everything was flat and weighted down…colette laurel sway back adjustment

Then traced off my pattern piece including all the markings where I want to remove the excess fabric in the back…colette laurel sway back adjustment

If you consider those markings as a dart , (essentially it’s the same structure) You could just treat those lines as dart markings and fold out the excess.  I’m using a slash and overlap technique here. Slice along the top dart leg. (Apologies for the poor lighting in these pics. Twas a very grey day indeed!) I should technically have left a little pivot/hinge at the narrow end. But I just sliced right through because I find the hinge thing fiddly. colette laurel sway back adjustment

Then overlap the pieces so that the bottom dart leg lies on top of the cut edge (or what was the top dart leg)…colette laurel sway back adjustmentcolette laurel sway back adjustment

Stick in place with masking tape and in my case, repeat for the second tuck. It’s at this stage when lined up against the straight edge of a ruler to mimic a straight CB seam, that you can see exactly the effect it is having. THAT my friends, is how curved my back is!! Crazy!! I actually held that up side on against the profile of my back and it totally is!colette laurel sway back adjustment

So. Hopefully up to this point this is all making sense. But here, for me is where I slightly depart from fully understanding the “why” of each stage and just start trusting that this works. Even though the next couple of steps, to varying degrees, may seem a little counter intuitive.

So I have my altered pattern. Now it’s so skewed that I need to “true” up various points to make it a useable pattern piece. I’ve stuck my pattern piece to my worktop with super wide masking tape, along the CB seam here. It stops it shifting around and gives me something to draw my new lines on. So firstly I want to square down from the neckline to the hem to give me a straight CB seam again. So here’s the counter intuitive bit right? I just curved that back seam. Why do I want to make it straight again? Well, my logic is telling me that the aim is not to curve the CB to echo the curve of your back but to shorten the CB and remove excess fabric. (The curve in the pattern above is a bi product of that rather than the actual aim) You still need a straight CB. You may also remember that after I’d taken the tucks out of my toile, the back became tighter. This step also adds some width back in at the CB to combat that….colette laurel sway back adjustment

The red dotted line is the outline of the  altered pattern piece. The straight solid pencil line is my new CB seam. You can see that it’s incrementally adding width back in down the length of the CB. I would imagine, relative to what we’ve taken out, but, in a different place. I’m beginning to understand this adjustment as a “redistribution” of the fabric to some degree if that makes sense? But please chime in if you can explain with more clarity!!

Below is the hem and CB seam.  Again, we need to square across from the side seam to the new CB seam. You can see the red dotted line shows how much the adjustment has skewed the hem. So by doing this, you can see we’re adding length back at the bottom of the CB seam (ie at the hem). This is the bit that seems the most counter intuitive. If we want to shorten the CB seam to counter the sway back issue, why are we lengthening it again? Again, my reasoning is telling me that we are redistributing that excess length that we took out. Moving it from where it’s not needed to somewhere else. But interestingly, when I measured it…it doesn’t add up to the total length of the tucks that I took out. And when I compare the length of the new CB to the one on the original pattern piece…it IS shorter by about an inch…despite the fact that it doesn’t look that way once the toile is reassembled with the new back piece! Weird right??colette laurel sway back adjustment

The final step is to redraw the side seam. With the original laid on top and matching the underarm and hem points, you can see how the adjustment has altered the shape of the side seam too.colette laurel sway back adjustment

Simply trace along the edge of the original pattern piece to get the side seam shaping back to what it should be. You can see that this will be removing overall width. So again, my reasoning is telling me that what we added in width when we squared the CB seam was more than what was necessary to bring the pattern piece back to it’s original proportions. So shaping at this side seam and removing a small amount of width in the process, is in theory bringing everything back into proportion in relation to the original pattern. I am not stating this as fact. This is me thinking out loud & trying to get my head around how this adjustment works. I know that it does work. But the geek in me needs to know why and how too!colette laurel sway back adjustment

With the new side seam drawn you can now see what will be removed from the side seams…colette laurel sway back adjustment

Now this is not a great picture (below) and if you’re viewing it on a mobile device you may not be able to see the detail. So take a look on a desktop if you get the chance…colette laurel sway back adjustment

My new pattern piece (above) with all the adjustments complete but before I cut it out. You can see the curved red dotted line at the CB and hem and the cut edge at the side seam. That’s the outline of the skewed pattern piece once I took those tucks out. The solid pencil lines are the new outline once I’ve done all the “trueing” and reshaping. You can see that a big chunk of width was added in at the CB when it was squared down, (look at the distance between the red dotted line and the new CB line) but some of that has been taken out again at the side seam when I reshaped it. (Look at the distance between the edge of the pattern and the newly drawn side seam).

Now, here’s the interesting part if you like a geek out! It may hold some clues as to why this works! With my new pattern piece all cut out, I laid it over the piece from the original toile. Although at first glance the piece appears to be the same shape as the original….look what happens when I line it up at the shoulders and armholes!!colette laurel sway back adjustment

Then look what happens when I line up the side seams…colette laurel sway back adjustment

WEIRD right??? The angles are totally different in relation to the original! Now, while I will not pretend I can thoroughly explain why this works, comparing those two pattern pieces and reasoning out what we’ve done, I’m forming a blurry idea of what’s going on in the big sway back mystery. It seems to me that the process is a combination of redistributing length (and consequently width) away from where it is not needed, and moving it somewhere else; and overall, reorientating the pattern piece.

Having said that I still don’t fully understand the why and how (mostly in relation to choosing where to square off from and to and why we add length back in at the hem); but I can prove to you that it IS what you do and it DOES work, because, well, look! I did it….and it worked!colette laurel sway back adjustment

I may revisit this on scale paper cut outs in an effort to understand it fully. Because it seriously bugs me that, although I know it works….that’s not enough! I need to know how and why. And this time I am going to make copious amounts of measurements and get all mathematical on it’s ass. If I have a eureka moment, rest assured I shall share because I know there are other geeks out there for whom “yes….but WHY?” is as common a question as it is for me. But for now, this is how you do a sway back adjustment!

A really good tute here just in case my pics don’t fully give you the full idea, btw 🙂


And in the meantime, if you have the ability to clearly explain what is going on with a sway back adjustment and why it works, or if you know of a blog post somewhere that clearly explains, not the how….but the why, then pleeeease tell! I’ve searched and searched the interwebs to no avail. Lot’s of “how to’s” out there. And I’m all like, “yes, yes , yes…but WHY do we square up here and not there and WHY do we add back length to the CB if we’re trying to shorten it???”

Yes, I am the adult version of that annoying child that repeatedly says “yes Mummy…but whyyyyyy?” until mummy screams and as a mental breakdown. 😉

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  1. Frances Danylishin February 18, 2016

    Thanks for a great tutorial and pictures on the sway back issue so many of us have. One thing I notice looking at your photos is that the dress is not hanging equally between the front and back under your arm. I read every fitting book I can get my hands on and I will relay to you an adjustment Sarah Veblen, author of “The Complete Photo Guide To Perfect Fitting” makes when adjusting the fit of a garment. She always reminds her readers after other adjustments are made to check side seams to ensure they hang equally between the front and back of the garment. When I look at your dress it appears that the side seam is too far back and should be about one inch forward (hard to tell the exact measurement from a photo). The seam allowances are removed. The amount of the measurement is removed from the front of the dress side seam and it is added to the back side seam of the dress. The seam allowances are added back in. I hope you don’t mind I mention this, but the sway back problem has been eliminated and it was the first thing I noticed looking at the “after” photos. Once again thanks for your blog .

    • Portia Lawrie February 18, 2016

      Hi Frances, I think this MAY have something to do with the fact that I am twisting round trying to take a picture of my back in the mirror, lol 🙂 Definitely all twisted up in that picture and not standing normally. Side seams definitely in the right place when not being a contortionist 😉

  2. Ellie February 18, 2016

    Excellent post, and something I have been wondering about. Thank you for showing us the modified pattern piece laid on top of the old one. I’m not sure I understand how *exactly* it works but it makes sense in a general way that changing the angle of the side seams with respect to the shoulders and armholes would change the way a garment falls. I would also love to know if anyone has a more detailed explanation. I feel like we’d be getting into physics or topology to have a really rigorous answer though.

    • Portia Lawrie February 18, 2016

      I think comparing those two pattern pieces is key to understanding it Ellie!! Except I threw my toile away in a huff and now I’m wishing I took more measurements, lol!

  3. KaSchu February 18, 2016

    Thanks for your very interesting post. I recently did a slash and spread for very rounded shoulders which of course left me with a very curved back seam. My eyes kept telling me I should straighten the back seam but my mind kept screaming “but, but then I’ll be taking out the length I just put in.” Your post has helped me make sense of it even if like you I’m not sure why. At least now I think I know where to begin fixing it. Hope you know what I mean. Thanks again 🙂

    • Portia Lawrie February 18, 2016

      I know! It messes with your head doesn’t it?!

  4. Sheryll February 18, 2016

    Thanks for linking to my tutorial Portia! It is great to see someone following it and having success!
    I’m a ‘why’ person too, so I’ll try to explain the logic. If you have a CB seam, and the adjustment is minor, you can often retain the CB curve that forms and forget squaring the CB seam.
    If you don’t have a CB seam, ie garment has a CB fold, you will need to square the CB like you did (because it is impossible to fold on a curve). Squaring the CB consequently makes the hem unlevel, like an upwards V – and we can’t have that – which is why it is squared too. The final reshaping of the side seam helps reduce some of the width that is added at the CB when it is squared, and also gives a nicer side seam curve. Hope that helps!
    Awesome work, your dress now hangs so much better, and if you wanted to you could add the back darts back in.

    • Portia Lawrie February 18, 2016

      Hi Sheryll! Thanks so much for taking the time to respond 🙂 I kinda get all of that. I get why we square. You just can’t have a pattern piece that shape, lol 😉 I suppose the main thing that messes with my head is when squaring the hem, where it meets the CB we are (or are we??)adding length back at the base of the CB. Essentially, lengthening it again when we just went to the trouble of shortening it. Why does that action not send you back to square one with a CB that is too long OR are we adding back less than we took out?

      • Imogheena Farandel February 19, 2016

        It has to do with the hang of the hem. I’ve been doing the exact same adjustments myself, (the Pattern Siccors Cloth tute is what I base the changes on too!). I think before adjustments, the hem line is distorted by the effect of the sway back a bit. If you look at your photo in the first post before any adjustments, the hem is pulling up a tiny bit. But the eyes focus on the excess in the back. Your dress needs length in that back hem, and less in the back area.
        It’s as if the back is ‘borrowing’ from the hemline as well as elsewhere, to get the fabric to sit across it in the shape the back needs. The horizontal darts actually exacerbate the hiking hemline! Making that v shaped hem more extreme. You’re just taken fabric out from where there’s too much and added it to where it needed more.

        Another element to consider is if you look at the line drawings of average versus sway back in Sherryl’s tute, the sway back actually has MORE length in it than average, because the curves are deeper. If you measured the curves along the spine, the sway back is longer than average, not shorter.
        I don’t think this comes into play so much with your shift as it’s loose enough to hang straight down from the shoulders, skimming your hips.

        But in a closer-fitting dress with darts and a CB seam, you will need that CB to be longer (where it’s needed!) not shorter.

        Gah so hard to explain, and I’m just nutting out the why too. I don’t have a definitive answer! just my own experience too!

        • Portia Lawrie February 19, 2016

          I love the phrase “nutting it out” lol!!! So yes, the “borrowing” element you mention is the thing that makes the most sense to me. Similar to a forward shoulder where the back shoulder is stealing length from the front shoulder and causing the front neckline to ride up in the process! Or the need for an fba where boobage steals length from the front pattern piece and causes the front hem to ride up! Hmmmm! I think we’re close to nutting it out! 😉 thank you!

  5. Michele February 18, 2016

    I love how detailed yet uncomplicated your tutorials are. Very easy to follow. You have such amazing talents. Have a wonderful day sewing your heart out. Cheers, Michele

    • Portia Lawrie February 19, 2016

      Michele that’s lovely!! Thank you! You too lovely lady 🙂 Px

  6. Joanne Burnett February 18, 2016

    A retired French Canadian tailor I took a tailoring class from taught us that the back will always take what it needs. I have a sway back also and a ‘forward’ neck. I always make the adjustments for my back first. You have to adjust your pattern before you can cut your garment.

  7. Jo from Three Stories High February 20, 2016

    Dresses always do that on me but I never thought of horizontal back darts. Genius! Thanks for showing us, it is hard work to put a tutorial together. Jo x

    • Portia Lawrie February 20, 2016

      Ah you’re welcome Jo! Yes it is alot of work to put it together but worth it if it gives someone the answers they are looking for I think! 🙂

  8. Simone February 23, 2016

    Sussex your tutorial today. Finally an answer to some of my fit issues. Many thanks.

    • Portia Lawrie February 23, 2016

      Awesome! So glad it helped Simone! Px

  9. Simone February 23, 2016

    *tried* your tutorial…

  10. Gailavon February 24, 2016

    I will be giving this a try thanks for the tutorial you did an excellent job .

  11. Deb August 25, 2016

    I’ve been reading and trying to wrap my head around this for weeks. I think finally this has sunk into my brain. Thank you so much. Your efforts to share this knowledge are very appreciated. Thank you thank you thank you!!

    • Portia Lawrie August 25, 2016

      Aw you’re welcome Deborah!! It does mess with your head a bit doesn’t it?!! 😉

  12. Deborah October 6, 2016

    Hi Portia

    I’ve been sewing for years but recently decided to start making my own patterns. I’ve searched the internet high and low about sway backs and have to say that your tutorial makes the most sense and is easy to follow and understand. The photos are very helpful too. But like you I can’t understand the logic of it either. 🙂

    So I’m going to give this a go tomorrow. Thanks for your help. Great work. 🙂

    • Portia Lawrie October 9, 2016

      Ooooh, good luck Deborah! Messes with your head doesn’t it, lol?!

  13. Adaline August 7, 2017

    •In House Patterns• posted a sway back tutorial on YouTube with the why; May 2017 :)))))


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