The four parts of this tutorial:
Post 1: Preparing your pattern
Post 2: Cutting and marking your fabrics
Post 3: Constructing the shell
Post 4: Inner support, stuffing, and mounting
Can you believe it? After today we will be about halfway done with our dress form construction. For such a complex process, it goes rather quickly!
In my first post, I covered how to take your measurements and record your body build, generate your pattern, and gather your supplies. In the last post, we prepared our fabrics, cut, and marked out pieces.
Today, we get to constructing our shell! Please note: if you want to receive email updates for these tutorials, sign up at the bottom of this post!
A recap: Bootstrap’s dress forms are custom-drafted patterns that you generate, sew, and pack, then mount on a stand. They come with an inner sleeve and support structure, and include cardboard and foam to bolster the base, arm, and neck. Bootstrap offers two versions: a misses size, and a plus size. They are both sewn by an identical process. Both forms correct for posture, shoulder shape, belly protuberance, and buttocks shape. There are also additional measurements you can take to customize the form: neck circumference, shoulder width, bust height, front length, back length, and back width.
If you are just now finding this series, you can find out how to generate the pattern and collect supplies in my first post.
So let’s get started!
We are beginning on the page that is headed with:
SEWING INSTRUCTIONS
DRESS FORM COVER
Before we start, I need to divulge two things. I topstitch along every seam, in this dress form. This is different than the pattern instructions, that suggest only the horizontal seams of the bust, underbust, waist, and hip. I topstitch along all vertical seams as well as the shoulder line. This is for two reasons: I love how this looks, but also more practically: it will help me in garment construction. By being able to see the center back through my muslin fitting, or the shoulder line, I can better make fit adjustments.
If you aren’t absolutely positive you can form perfect seam allowances, or if you are a beginner or an intermediate stitcher, you may not want to topstitch the center front and center back, as those seam allowances are used later to affix to the inner support. Don’t worry too much though – if when you get to the inner support (my next post) you find your topstitching has hindered your ability to affix these supports to the inner seam allowances, you can pick out your topstitching.
Secondly: I go a little out of order on the directions, here, when it comes to staystitching the neck and armholes. Otherwise, as per the last entries, I follow the instructions in the order written.
I was so pleased to find that the notches on the pattern, always line up. Here, we are stitching center back pieces to side back, matching notches. Stitch exactly at the 3/8″ seam allowance (or whatever seam allowance you employed, if you did your own):
After you join these panels, you will find your traced lines line up perfectly, along the horizontal locations of bust, underbust, waist, and hip. Remember I made a faint line for mine:
Clip these allowances about 1 5/8″ apart:
And then press open. We will be pressing open every seam on this form’s shell. It is good advice to have some pressing tools with curves (like a tailors ham and roll), for many of the seams you’ll be pressing.
Now it is time to pin and stitch our cups, as well as our lower side and lower center fronts, and upper side and center fronts. We will be following the same procedure as the first two seams; stitching, clipping 1 5/8″ apart, and pressing open.
The cups are the pieces most easily confused with one another – this is one reason I suggested keeping the paper pieces with the pattern right up until we stitch:
Now after we join these six pieces in three sets, we have our upper and lower fronts, as well as our cup. Clip and press seam allowances:
Now, we will sew the cup to the lower part of the form.
The cup seam is the trickiest in the entire dress form. I clipped the lower side-and-center assembly’s raw seams at 1/4″, before pinning and stitching with the cup side down. This helps the natural gathering motion of the feed dogs to ease this curved seam together.
Shown below: a finished cup, before any pressing:
Now before we press, we can look at this seam. You will see at right, my clipped seam allowance on the lower-side of the seam. At left, the cup’s seam allowance. Like most curved joins, we want to notch out the fullness in that cup seam allowance, and clip the curve in the concave (lower) seam allowance. Note I’d already clipped the lower side before stitching.
Shown below, after careful pressing:
Now this is a fun part – we get to topstitch the cup here! As I’ve mentioned, I topstitched all my seams – horizontal seams first, then vertical seams. I used a golden heavy thread for the horizontal and cup seams, and a scarlet heavy thread for the vertical seams. Stitch slowly, making sure the seam is pressed flat as you travel over it:
Now, we stitch our upper front assembly to the lower assembly, carefully matching the princess seams:
The directions now call for you to hand-sew along the horizontal lines of underbust, waist, and hip. I simply made sure my chalk lines were heavy enough.
Next – missing from the instructions – we need to stitch our side seams. I also notched here at the more severe curve at hip:
I then carefully pressed this seam open on my tailor’s ham:
Then, I stitched the center front seam, clipped, and pressed. This is really coming together!
Time to start stitching those horizontal lines – bust, underbust, waist, and hip. At the underbust join to the cup, I carefully pulled my threads to the backside and knotted them.
Looking good!
Now time for all the horizontal lines (except the center back), seven in all. I used a red thread for these:
Now this is the point where I stay-stitched the armscye. It doesn’t matter when you do it, though, really.
I stitched the shoulder seams and topstitched them, in preparation for installing the neck.
After stay-stitching the neckline on the body (bottom of step 9 on the directions) and the top edge of the neck piece (step 10), I installed the neck. The neck is notched and you will find, an easy fit:
I went ahead and topstitched this seam, after clipping and pressing open:
Stitch the center back seam, clip, and press open.
And now, for the most annoying topstitching seam in the whole experience – the center back seam! You will be stitching from the top side, up from the bottom of the now-closed form assembly. Sew slowly, always adjusting the work to make sure you are not catching the wrong layers. The larger the dress form you are making, the easier this seam is. By the end of this seam you are kind of stitching in a tunnel. But it is not the hardest closed topstitching seam I’ve constructed!
Here is my last bit – finishing up to that neckline!
Voila! We are ready for our next steps – installing the neck top and armholes, and putting together the inner structure!
So there we have it! Great job today!
Next up, we put together our inner structure! If you have any questions, please feel free to comment here!
Late getting started? Pick up your pattern here: MISSES or PLUS

I am really enjoying these detailed instructions. Your sewing in visible seam lines and horizontal lines is genius. Did you spend any time verifying measurements? I plan to carefully verify my shoulder shape, including defining my forward shoulder and high back bump.
Wow! I’m very impressed – you’re making it look very easy. Great tutorial – thank you very much. I’m very tempted to have a go at making one for myself now.
Hi Kelly I recently completed my dress form and posted it on the McCall Pattern Facebook page I enjoyed and used your step by step measurements and construction tips and posted your blog as something to check out Thanks
Andrea
I see Bootstrap Fashion has added a pattern for arms. Any chance you will be adding an arm– and blogging about it? (fingers crossed)
Would I have an easier time of top stitching centers front and back if I first added more seam allowance there, making it 1/2 or 5/8 inch instead of 3/8? Then I would have a larger seam allowance to work with when attaching the inner structure?
Hi Sheri!
Yes! I had the 3/8″ seam allowance and I was able to get the topstitch and inner support attached. But I’d recommend adding more – a 1″ seam allowance, to be sure. I am going to make those notes in my tutorial.
Thank you!
Hello Sheri!
I am not going to be sewing up the arm, at this time. Have you checked out Andrea Davis at SewToFit? She is leading a vlog series on this form, and she may be sewing up the arm. You can find her vlogs on her YouTube channel. Thank you for your comment!
I’m so glad you enjoyed the posts! And – good job completing the dress form!
Hi Kathy! I only verified while stuffing – as the pattern recommends. I visually verified the posture, buttocks shape, etc and was astonished how good the results were!Let us know how your results go.