How to Make a Bodice Pattern – Draft a Sloper or Block

Hey y’all – welcome back to fitting month on the blog! Today I’m going to show you how to make a bodice pattern. Now you may wonder what drafting a pattern has to do with fitting ready made patterns, so let me tell you – if you know what your 2 dimensional shape is, it becomes easier to evaluate other two dimensional patterns to see what you’re going to need to adjust.

Note the drafting in this post isn’t meant to be a wearable bodice but an exact flat pattern copy of your body that you can then use to see how much design ease a pattern has and where you might need alterations. Slopers or blocks are then traced and ease and style lines are added. Take the neckline for example – you need to know exactly where the base of your neck is before you can lower it or add a collar, because if you just draft a random neckline you won’t know how much to lower it without the base of the neck reference point – it would all just be a shot in the dark.

So let’s get started. Start by measuring yourself. Last week’s post has the video on how to measure yourself as well as the printable measurement card. You’re going to need a few more measurements besides those on the card – read below to see how to get them.

To take the across shoulder measurement, measure from the point of one shoulder straight across to the other.

To take the shoulder to center waist measurement, measure from the same point of the shoulder across to the center front of the waist (approximately in line with your belly button) and at the center back (in line with your spine). On the front measurement, mark the tape where the point of your bust hits – you’ll need to know both the front shoulder to center waist and the shoulder to bust point measurements. Note that your front and back measurements probably won’t match if you have boobs – the front will be longer. As it should be – you need more fabric to go out and over breasts.

For the armpit to waist measurement, go back to that part where you had the string tied around your waist and the ruler under your arm. Measure from the top of the ruler down your side seam to the waist string.

Got those? Good, let’s draft. You’re going to need a long ruler (at least 18 inches), a pencil, and a large piece of paper (pattern tracing paper, exam table paper, kraft paper, newsprint, butcher paper, baking parchment paper and gift wrapping paper all work well).  A flexible ruler like this one or French curve ruler (affiliate links) is also helpful.

*Important note before you begin: your bodice may not look like mine. In fact, you may be shocked at how different it looks. That’s OK, and that’s the point! The first time I drafted a bodice based on my measurements instead of standard measurements for my size, I really, truly though I had done something wrong. I had never sewn anything that had an armscye shaped like what I had drafted. I discovered I was going around thinking clothes fit when they didn’t, and the bodice that didn’t look like it was “supposed” showed me that when I sewed it up and it fit better on the first try than anything I’d ever made before.

Important Note 2 – PERSONAL HELP: If you’re looking for more help or my methods just aren’t making sense for you, these books are excellent and can provide you with much more information than my post does. And many of them are available in local libraries. I am not able to provide personal bodice drafting guidance, so if your question is not answered in this post please look to the books in the post linked above.

Important Note 3 – What we are creating here is a sloper, which is meant to fit like a second skin. That way you have a flat pattern representation of your body, and any other modifications come AFTER. So you would use your well fitting sloper and then retrace and modify to a V neck or a dropped waist or a side dart or a looser fit or whatever design details you want.

We’re going to start with the front bodice. Use your ruler to draw a long vertical line.

1. On the vertical line, mark off the center back length. At the top of the line, measure out 1/2 the across shoulder width. Make sure this is measured out at a 90 degree angle.
2. From the corner, measure horizontally 1/5 of the neck measurement plus 1/2 inch. Measure down 1/5 the neck measurement plus 1/4 inch. Draw a curved line to connect the two.
3. Draw a line from the center front bottom to the point of the across shoulder line.
4. On that diagonal line, measure up the amount of the shoulder to center waist  and make a mark.

5. Connect your two marks to create the shoulder line of your front bodice. Then measure down from your new shoulder point to the bust point.
6. From the bust point, you’re going to need to mark your dart. To determine your dart, subtract your high bust from your full bust measurement. The amount of difference is the dart you’ll trace from this download (The dart paper size doesn’t matter, just make sure you are printing through Adobe and choosing “actual size” or “100%” or similar instead of anything like “scaling” or “fit to page”.  You can check by measuring one of the lines – it should be 4.5 inches or 11.4 cm long). Line the point of the dart up with the bust point and trace the dart for your size. If your difference has a 1/2 inch, you can trace between two lines.
7. Extend the vertical dart line down to meet the waist line, then measure it, then measure the other dart leg to make sure it’s the same length.
8. Draw a 90 degree line from the second dart leg extending out toward the side seam. Measure the two blue lines at the bottom of the bodice – together they should add up to 1/4 of the waist measurement plus 1/4 inch (for ease).

9. Measure out from the center front 1/2 of the front bust measurement (not full bust – this diagram has the wrong wording – sorry!) plus 1/4 inch (this is for ease). Draw a vertical line at this point – this is a guideline.
10. Draw a line that is the length of the armpit to waist measurement that touches the corner of the bottom of the bodice and and the vertical guideline from step 9.
11. This is what the side seam looks like without the words in the way.
12. Where the side seam touches the vertical guide, draw another horizontal guideline. Measure along this guideline from the center front 1/4 of the high bust measurement and make a mark.

13. Draw in the armscye curve. The fuller your bust is, the deeper this curve will be. The curve should come in to touch the guideline from step 12 before curving up toward the shoulder. Make sure the curve starts and ends at a 90 degree angle to the side and shoulder lines.
14. You’re done with the front bodice!
15. To start to back bodice, draw a vertical line. On the vertical line, mark off the center back length plus 1/2 inch. At the top of the line, measure out 1/2 the across shoulder width. Make sure this is measured out at a 90 degree angle.
16. From the corner, measure horizontally 1/5 of the neck measurement minus 1/8 inch. Measure down 3/8 inch. Draw a curved line to connect the two in the neckline. Then, from the bottom of the neckline, measure down 1/5 of the armscye depth plus 1/4 inch (Not minus 1/4 inch as the diagram says – my mistake – I was drawing these late at night) and make a mark. Draw a horizontal guideline at this level.

17. Measure up from the bottom of the center back up toward the guideline the amount of the center back to shoulder measurement. Then draw in a shoulder line from the end of the neckline to this point.
18. From the center back, measure horizontally 1/2 of the back bust plus 1/4 inch (for ease) and draw a vertical guideline. At the bottom of the center back line, draw a horizontal line at 90 degrees that is 1/4 of the waist measurement plus 1 inch (for the dart) and 1/4 for ease. (So 1/4 waist plus 1 1/4 inches).
19. Mark a line that is the length of the armpit to waist measurement that touches the waistline and the guideline from step 18. Depending on your back bust measurement, this line may be very angled, almost vertical, or  even angled out.
20. Draw in the back armscye. This curve will likely be shallower than the front bodice, unless you have a very broad upper back and narrow back waist.

21. Measure the shoulder seam. Make a mark at the halfway point, then draw a vertical guideline straight down from that point to touch the waistline. Draw in a 1 inch dart that starts at this line and goes up to touch the guideline that is even with the armscye.
22. Compare the front bodice and back bodice at the shoulder. You may find that the back shoulder is longer than the front. If so, you’ll need to add a small dart to the back shoulder. Measure the difference between the two.
23. If the shoulder dart is needed, make a 3 inch long dart at the center point of the shoulder that is the width of the difference.
24. You’re done with the back bodice!

To sew up a bodice to test, add seam allowances to the side seams, shoulder seams, and center back. Baste in a zipper and sew the darts, shoulder and side seams.

Now in a real bodice, you’d move the points of the darts down depending on the cup size, but for fitting purposes and comparing to ready made patterns to get an idea of needed adjustments, we’re not going to get into that discussion. So this bodice should fit with the points of the darts ending on the bust points.

You can see the bodice on my dress form below. Now, while our measurements are close, they are not exactly the same. You can see this because my bodice is above the waist of the dress form and stretched across the back – I have a narrower back and higher waistline that the dress form. Your bodice will likely not fit a form either- most people’s don’t!

Here’s the bodice on me. You can see it ends at my waist, the edges reach the points of my shoulders, and the dart points end on my bust at the points. The armscyes unfortunately got a little stretched out at the edges and the waist wrinkled from forcing this onto my dress form first, but they’re close.

This is the side view – the important thing here is the make sure the shoulder seam is centered and that the side seam hangs straight down your side. If it pulls to the front or back, you need to adjust by subtracting from one side seam and adding that same amount to the other. You also want to check that your front waist is even with the back – which is easier to do when you aren’t trying to move your arm around for pictures and causing the bodice to tilt because of that.

And in the back (wrinkled both from the dress form and moving to take pictures of myself) you can see that I have appropriate room at the shoulders tapering down to my waist thanks to the back darts.

Phew – that was a long post, but I hope you can now draft a bodice that fits your own special shape. In the next post we’ll cover how to take that draft and compare to patterns to figure out where to start making fit adjustments.

To see how to make a sleeve, check out this post.