On the Strictly Ballroom Dress, on both on me and on the dress form, there’s a tiny bit of fabric pooling at the lower back. It would be okay if I left it, but so much better if I fix it up!
Here’s what I did to make this adjustment. There are a lot of photos, but it’s fairly easy to do!
UPDATE: I made a math error on this adjustment post! Thanks to Phoebe for pointing it out. I’ve corrected the words but the photos will still be doing the wrong thing.
First, I pinned out the amount needed on the muslin while it’s on the dress form, taking a horizontal tuck across the lower back. I tried it on one more time to make sure the tuck solved the problem.
Now, we’ll transfer the changes to the pattern pieces.
First, we’ll measure this horizontal tuck at centre back and at the dart points, to determine how much we need to adjust out of our pattern pieces.
I’m measuring in the middle of the back, at the widest part of the tuck. It looks like I have a 3/8″ tuck, so I’ll write that right on the muslin for easy reference.
I also measured how far up the tuck is placed, above the waist seam. This will help me place the tuck at the exact same point on the pattern piece! I’ve taken this tuck at 2 3/4″ above the waist seam. (In case this is confusing, it’s not a real waistline seam, but a dropped-waist around the hipline.)
Last spot to measure is at the dart crossing. We’re taking in 1/4″ where the dart and tuck meet. This measurement will help us to taper the tuck properly when transferring it to our pattern pieces.
Now, let’s make these changes to the pattern tissue! First off, I’ll measure the seam allowance from the lower waist seam, to be certain we’re placing this tuck at the right spot on the body. Remember we measured upwards from the waist seam? We’ll need to measure that from the seamline, not the raw edge of the fabric.
Now we’ll measure the distance up from the seamline – 2 3/4″. Make a small horizontal line to mark this point.
I also measured this same distance along the dart line, and made another small marking so we can connect these dots.
Draw a straight line connecting these two points, all the way across your pattern piece from centre back to sideseam.
This line marks the bottom of our tuck. We’ll draw a second line to mark the top of our tuck, creating a wedge-shaped triangular piece. Then we’ll fold the two lines together, just like we did in the muslin!
This is where the mistake happens – I made a 3/8″ adjustment, when I should have made a 6/8″ adjustment or 3/4″! Remember to account for the entire tuck, not just half of the amount like I did.
Remember how deep our tuck was, at centre back? It was 3/8″ at the centre. We’ll measure up from the first line and make a mark 3/8″ above make a mark 3/4″ above, twice the amount of the tuck measurement. Then draw a straight line connecting this marking to the first line, at the sideseam. Does this make sense? See the long, narrow, triangle on the pattern piece below?
Now, simply fold up the tuck we’ve drawn in, like it was a dart!
Tape this tuck in place. We’re almost done!
Tip: Measure from the top of your pattern piece to the bottom along the centre back line. Now measure the same place on your muslin, with the tuck in place. Do they measure the same amount? If they do, then you’ve done the math right! This would have saved me from making my mistake.
How straight is your centre back line now? Mine is crooked, now that we’ve taken the tuck out. Simply re-draw the centre back line from top to bottom. A slight bit will be added to the centre back, but not enough to matter!
And that’s it! Our pattern piece now has the same horizontal tuck as the muslin does, which should solve our fitting problem.
That’s what I did to fix up this problem – I referred to a couple of different sewing books to see how they dealt with this fitting issue. Any questions on this adjustment? Is this the same method you use to correct for extra fabric pooling at the lower back?
Any tips or suggestions to add to this demo? Leave a comment below!


Thank you for sharing this….This is exactly the same way I have done it in the past..Works great…..I just love reading your posts…Always informative, exciting and can never walk away till done reading….I even let my voice mail pick up during this one, just cause I wanted to see if it was the same way as I have done it throughout and sure enough it is!!!
Louise
Slave To My Needles
Thanks for this. I understand the muslin process but always get hung up as to how to transfer my changes to the actual pattern pieces. Your step by step explanations here & before make it so clear.
Thank you for such a clear tutorial. The pictures really help. I do have a question about the dart. I noticed that the dart line, like the centerback is also not quite straight. Do you straighten it at all? I wondered if you would need to move the bottom point over a very small amount and straighten the lines.
Ah, yay!! This couldn’t be better timed for me thank you! Do you mind if I reference you in my Draftalong?? We’re covering fitting issues right now and this is one adjustment I’m certainly going to need to carry out on my own toile and pattern.
Px
Maybe I’m not looking at this right, but if your original tuck was 3/8″ deep, don’t you want to remove 6/8″ from the pattern piece, because the tuck is essentially doubled up fabric? On the pattern, you’ve drawn your lines 3/8″ apart, but then folded them up, so isn’t the tuck on your pattern only 1.5/8″? Or am I being hugely dense?
The few times I have done a tuck such as this, I have made a much deeper tuck than you do. This means that the centre back line is quite crooked, and it adds quite a bit more extra fabric if I straighten it. Is there any way to avoid this? Can I just sew a curved back seam (which is what I have done in the past…)
@Phoebe: Oh my gosh, you’re right! Thanks so much for pointing it out. Off to edit this post and make it right.
If you’re making changes like this to your pattern, a good way to double-check is to measure the centre back from top to bottom, both the muslin and the pattern piece. If they measure the same, you’ll know you’ve taken the right amount of tuck! (Which would have caught my little error here..)
@Anna Christina: I’m going to leave my dart lines as they are, and not change the angle or any of the dart points. If I look at the photo of my muslin (with the tuck in place) the dart lines look straight to me, so I’ll leave them be!
@Portia: Of course! Glad it helps!
@JillyB: Yes – that was the other thing the book mentioned, if you already have a centre back seam you don’t have to straighten it, just sew the seam along the new, bent lines. If you don’t mind the look of a centre back seam, then it’s OK to add one too.
Thank you–I do that adjustment, as you do. I also correct my shoulder width the same way.
Thanks for the tutorial Tasia. It’s helpful seeing how the change in the muslin is translated back to the original pattern. I’ll save this away for future need!
Great post. Thanks for adding such detail. Can’t wait to see the finished dress.
Pooling at the back waistline can happen for a couple of reasons. The alteration you show here helps when the back piece is too long at the center back…not the sides. Pooling can also happen when your torso is shorter all the way around, in which case, you’ll need to make an even tuck (not a wedge) on both front and back pieces. If you feel you have a short upper torso and/or high hips, then you might want to consider this alternative :) HTH
Love this post, very informative!
I found this very useful. Sometimes it is difficult to figure out how to transfer a ’3D’ alteration to a muslin onto the flat pattern.
I love marigold. Apparently it is very trendy this winter. Tha pattern tis awesome too.
Perfect tutorial! It’s just what I need for my self-drafted pattern that just isn’t perfect yet… Thanks for sharing!