• No Products in the Cart

How To Draft A Back Bodice Sloper

It’s back! How to draft a basic bodice block is back! Last week, I posted a how-to on how to draft a front bodice block (click here to see) and I was surprised to see how many people were interested in such a topic. I was sure I was the only geek who would be interested in such a thing (I have memorized the formula. How sad!). My post was even featured on Stitching Spotlights on the blog A Fashionable Stitch (click here to see).

I planned this feature to be monthly but since there was so much interest, I will keep going with it. With that said, today I will show you how to draft the back bodice block so that you have your front and back block patterns. But don’t you dare cut your muslin yet! When the sleeve pattern is drafted, adjustments to the front and back armholes may be needed. Also, the pattern needs to be trued and shapes need to be evaluated (i.e. neck, armhole, waist). These will all be the subject so follow up posts so stay tuned!. Plus, taking a week to ruminate over each step will help you understand why each mark was made and what each step means. This, in turn, will make you a better pattern maker as well as a better evaluator of fit.

First, we must measure and record a couple of measurements. I apologize and admit that I glossed over how to measure a human figure or a live model (as oppose to a form) in my last post. Since accurately measuring is crucial to achieving a good block, I took more time (and sketches and words) to explain how to properly measure.

What is worn while measuring is very important. Take your measurements while wearing a pair of leggings, workout pants, or any tight fitting and thin pair of pants and a bra that you most commonly wear. Draw or mark all critical points such as shoulder line, shoulder tip, armpit, side seam line, CF line, etc. with a permanent marker or other pen (I will show you how to find these points below). The points are needed for several steps and you don’t want to be guessing where each point is for each step.

Stance and breath is also important while measuring. Be sure to stand upright and on a flat surface, with feet slightly apart and weight distributed evenly. Also, breath normally while measuring as any large inhales or exhales can distort measurements.

How do you draw or establish CF or CB? Use the hollow at the front of the neck and the prominent bone at the nape of the back of the neck to draw a line plum to these points.

Circumference measurements – neck width, waist arc, bust arc, back arc – are tricky to measure. All can be measured in two ways. The first way, the textbook way, is to take the circumference measurement and divide it by four. My problem with this is that front and back widths can vary from person to person and front and back widths are not the same. Some people have a larger tummy than others, making the front waist measurement disproportionally larger than the back waist measurement. My solution to this problem is to establish a side seam and a shoulder seam (with a permanent marker) and then measure arc and width measurements. When taking waist, bust, and back arc measurements, add 1/8″ ease to each for ease. Like I have said before, 1/8″ doesn’t seam like a lot but it equates to 1/2″ in the round.

Waist, back, and bust measurements are easy to measure but you may be wondering how to measure front and back neck width. To measure these points, tie a chain/tie/elastic loosely around the neck, allowing it to rest at the neck base. Then measure from CF neck (hollow at front of neck) to shoulder seam and along curve for front neck width and from CB neck (prominent bone at nape of back neck) to shoulder seam and along curve for back neck width.

Lastly, dart placement is a standard measurement – ¾ less bust span. Easy enough!

With that said, measure and record the following measurements. I included a diagram for even easier reference.

1.    Full length

2.    Center back length

3.    Shoulder slope

4.    Across shoulder

5.    Back neck

6.    Waist arc

7.    Side seam length

8.    Back arc

9.    Across back

10.  Shoulder length

A-B: Full length

A-C: Across shoulders, squared from A

Square a line down 7” from C. This will be a guideline for drawing armhole

B-D: Center back length

Square a line out 4” from D. This will be a guideline for drawing neckline

B-E: Square a line out from B equal to waist arc plus 1 ½” (for dart)

E-F: 3/16” squared down from E (on B-E line)

B-G: dart placement, measured out from B

G-H: 1 ½”

G-I: ½” G-H

B-J: Side seam length (on B-D line)

J-K: Square a line out from J equal to back arc plus 1/8” for ease. It may not seem like a lot but 1/8” on front and back pattern at this point with be ½” in the round.

J-L: B-I

L-M: ¾” squared down from L. This will become dart point

Draw dart legs by connecting point M with points G and H and extending line down 1/8” at each point (see sketch). After, draw a curved line from point G to B and point H to F using a curved ruler

B-N: Shoulder slope with N falling on C guideline

A-O: Back Neck

Draw a line from N to O. If this measurement does not equal shoulder length plus ½” for dart, it is okay to extend or shorten the line accordingly

Square a line down from O to D guideline and label P

P-Q: ½” with line at a 45 degree angle from P

Using a curved ruler, draw neckline with line touching points D, Q, and O

O-R: ½ O-N

With a ruler touching points R and M, draw a line 3” down from R and label S. This will be shoulder dart point

Mark T by measuring ¼” out from R (on O-N line towards neck – see diagram) and square up 1/8”

Connect T with points O and S

Mark U by measuring ¼” out from R (on O-N line towards AH – see diagram) and square up ¼”

Making sure T-S and U-S are of equal lengths (adjust as needed), connect U with points S and N

Draw a line from K to F

K-V: ½” down from K on K-F line (this will become bottom of armhole. It is somewhat standard that armhole should be ½” – 1” below armpit)

D-W: ½ of D-J plus ¾”

W-X: Across back plus 3/16” for ease (plenty of room to raise arm up and in front of you)

Using a curved ruling, draw armhole with line touching points N, X, and V. Armhole should be somewhat straight from shoulder tip to mid-armhole and then scoop under to meet SS. Make sure that line is at a 90 degree angle when it meets SS.


  1. Reply

    Sewing Princess

    This is fantastic Maddie! thanks a lot for sharing your knowledge!

  2. Reply


    these are awesome tutorials! i’ve been working on my pattern block for some time trying to perfect the fit. i’m definitely bookmarking these to come back to!

  3. Reply


    Wow, thank you SO MUCH for doing this, I’ve been trying for so long to make one but it’s never turned out right!

    • Reply


      I’m glad you ladies enjoyed. It’s a great refresher for me as well as any experienced sewer. I’m excited to get started on the sleeve!

  4. Reply

    Ellen Mason

    I don’t think I have ever anticipated a sleeve like I am right now. This series is fantastic.

  5. Reply


    Thank you thank you thank you!

  6. Reply


    I love this post I can’t wait to see the other tutorials!!!!!

  7. Reply


    I love your blog!! And I linked to this post today.
    Thank you for sharing your knowledge online. It really helps!!

    • Reply


      You just made my day 🙂
      You’re a doll

  8. Reply


    You’re the best for this series! Once I have a couple projects finished, I am totally coming back to this 🙂

  9. Reply


    Fantastic! Love your tutorials…have you done a sleeve sloper as yet? Can I do a search on your site ? i am trying to find this tab or maybe monthly listings of what you have posted but can’t seem to find how to go about doing a search on your site…any tips would be great.

  10. Reply


    Wow! This is amazing! Thank you for emailing the link to me.

  11. Reply


    this article has changed my life, when i read it and followed it, i was also happy.http://www.kitsucesso.com

  12. Reply


    Im having  hard time figuring out what Ive done wrong, I re measured and re drafted the whole thing but my arm hole is still incredibly small as compared to the front part. Thanks for this tutorial its been easy to follow up until this last point!

    • Reply


      Hey Holly,

      Thanks for reaching out to me! I’m very glad to offer help. I always have a helping hand to lend 🙂

      Can you have me more details about what you’re having trouble with? Your armhole is small compared to the front part? What is “front part”? What is your armhole straight measurement? How did you measure the armhole when measuring yourself?

  13. Reply


    thankyou for these instructions.  can u help me out?  i don’t understand how long to measure b-g.  how do i figure out the dart placement? 
    you said, “dart placement is a standard measurement – ¾ less bust span. Easy enough!” but i can’t get my head around this sentence.
     thanks in advance

    • Reply


      Hi Monica,

      Thanks so much for reaching out! I hope I can answer your question. If you need more help, you can always email me directly (Maddie964@aol.com). 
      Dart placement is the same for front and back, which is 3/4″ less than bust span. So if my bust span is 3″ (bust span = bust point to bust point. My bust span is 6″ but when drafting the front and back bodice slopers, I halve the measurement because the pattern piece only deals with half the body), then my dart placement is 2 1/4″ (3-0.75). Does this make sense?

      • Reply


        thankyou.  very clear and good to go.

        • Reply


          Yay! I’m happy to hear that!

  14. Reply


    hi maddie, why is it 7″ squared down from C? Is that a standard measureemt for drafting a armhole? i’m Asian so just wondering… usually i did a 8″ or 9″ instead. tq

    • Reply


      I don’t think there is any rhyme or reason to 7″ and I believe 8″ or 9″ could be used without affecting the outcome of the draft. The line doesn’t become a part of the pattern – it’s simply a guideline. It has to be long enough so that line BN and ON reach it. I’m sure 4″ or 5″ would be enough but it’s better to err on the larger side (for larger women). Does this make sense?

  15. Reply


    Hi Maddie

    for step B-G, what angle is it? thanks!

  16. Reply

    Anupriya Sharma

    H Maddie,
    Do the front and back measurements have to be the same for side seam length, shoulder length and center back length

  17. Reply


    Hi Maddie, I am a green horn and I totally love what you do. I have spent the whole day going through this. Where is point U on your diagram? I don’t understand how you measured it towards AH. Please explain.

  18. Reply


    Hi Maddie am here again!!!!!

    while drafting the back neck the line N-O does not match my shoulder length plus 1/2″, you said it was okay to extend, my question is which way should i extend the line towards? should it be inwards towards the A-C guideline or outwards on the C-N line.I tried extending outwards but am getting a funny shape for the armhole.

    secondly is it compulsory to add the shoulder dart?what if i don’t want it?


    • Reply

      Maddie Flanigan

      Hi! Yes, extend the line outwards on CN line. You do not want to change the back neck width (read my post on back width to find out why).

      As for the back armhole , what is your across back? Is it 1/2″-1″ less than your across shoulders (read my post on x-shoulder, x-back, and x-front to find out why)? If not, redraw back armhole with this x-shoulder/x-back relationship. Does this fix the problem?

      You don’t have to have a shoulder dart but if you eliminate it, transfer the dart into ease – the back shoulder length will be 1/4″-3/8″ longer than front shoulder width and eased while sewing.

Leave a Reply