Modeling the Body’s Curves
As previously discussed, the problem with a body with curves is that it operates on curved lines instead of straight ones. To make our straight block into a curved block, we’re going to take out long triangles along the Waist line (or Bust line, for those with a smaller Bust).
First, we need to decide where to do our taking out. For most figures, you can divide the body like this: (We’ll cover an exception later)
Now we can start marking in the triangles that will let us bend the block to better match the body. To do that, we need to do some math to figure out just how much to remove. There are three lines that we’ll be working with: the two mid-lines we just marked, and the side line. The Back midline will have difference based on the back measurements removed, and the front midline will have difference based on the from measurements removed. The side line…. Well, the back side of the side line will be based on the back measurement, and the front side will be based on the front measurement. (Did I mention that the female torso is not really a regular conic section? Weeeellll….) What this means, basically, is that we’re going to remove the extra front from three places (both sides of the midline and the front side of the sideline). Ditto to the back. The amount we’re removing is based on half the difference between the Bust and Waist Front (or Back). Half? We started our block with half of the Bust Front and Bust Back measurements, on the assumption that your body is pretty close to matching between the right and left sides. So, you need to compute:
1/6(Bust Front – Waist Front) = Front Triangle Base
1/6(Bust Back – Waist Back) = Back Triangle Base
If you are working with a larger Waist than Bust, please reverse accordingly.
The triangle at the Side line is shorter. If we were to extend it all the way up to the Bust line, we’d be removing area from inside the Armscye. Since the area inside the Armscye is destined to be removed anyway, this will cause some problems (notably, the Armscye will be shrunken down where the triangle intersects it).
Next, we’ll begin marking the armscy out…
Oh my goodness- you’re talking about renaissance costuming and actually DEALING WITH ARMSCYES. Most instructions just say things along the lines of “draw an angled line” or the even more helpful “add straps.”
Thank you thank you thank you!
You’re welcome. :) It’ll get even better once I finish the photography for the straps and tackle the over-bust portion of the draft…. ;) I swear to you, I could geek out for pages about how the invention of the fitted armscye is one of my favorite feats of tailoring geometry between 1400 and 1700 (and yes, it took a couple hundred years to get the curves all right rather than relying on bias stretch). Actually, what with me being me, I might just rock my geekiness on that some day,,,,
Hmmm…. Somehow my armscye to waist measurement is 1/2 an inch above my bust line. What should one do in this instance? Did I measure the armscye to waist wrong?
Hi, Laura – That might just be how your body is shaped, but check to make sure you followed the directions I posted for taking your Nape-to-Waist measurement. When you look at a woman’s body, the armscye appears to be significantly above the bust line (unless she’s had a very bad plastic surgeon!). If you take both the Armscye-to-Waist and the Nape-to-Waist measurements absolutely flat to the body, the armscye to waist will be the larger of the two. This draft is based on taking the nape to waist measurement so that it reflects the mound of the bust, rather than being tight to the sternum. (I just checked mine as a reference – my armscye-to-waist is 7.5″, my bust-to-waist is 8.5 taken on angle from the level of the chest in to the waist but only 7″ if I take it flat against the body. Mind you, I’m wearing a sports bra, so things aren’t exactly in their ideal position right now.) Because the bust angles away from the body, many women will find that the distance between their bustline and their waistline is actually slightly longer than their armscye-to-waist length. (That’s triangles for ya…. The Hypotenuse is longer than you’d think.) We’re taking the measurement that way to avoid a lot of fussing and guessing about the size of the chest – taking the measures in a way that reflects the curve of the bust guarantees that the resulting block will accomodate the bust. The entire bust, which is pretty imporatant.
There are three exceptions where I’d expect the Armscye-to-Waist measurement to be longer than the Bust-to-Waist (that I can think of off hand, at any rate). If you have extremely pendulous breasts and do not wear a supportive bra, you’ll find that your bustline is much closer to your waist and the measurements will reflect it. If you are extremely flat-chested, you’ll also find that your armscye-to-waist measurement is longer, because your bust doesn’t angle away from the body significantly. Also, if you have a significant curvature to your spine, that can lower the bustline. I’d like to add a list of watch points to the second half of the article, so thank you for asking. If you retake the Nape-to-Waist/Nape-to-Bust measurement and there’s no change, you’ll want to make the tick for the Armscye-to-Waist measurement on the sideline slightly above the Bust line, and your middle triangle will be taller than than your side triangles. That’s totally fine- bodies tend to be custom jobs.
Such a good tutorial, thank you! And I would love to hear you geeking out about armscyes. They still scare me. I can’t wait to try this out!
Sanna – Armscyes aren’t that bad, once you get the hang of them. The problem is that they have to transition between about 5-7 separate planes on the body (ie, relatively flat areas) – the side, the bust side, the upper chest, the shoulder point itself which can be flatter or rounder depending on build, the back shoulder and the back side. Each time we have to make a flat thing, like cloth, transition from on plane to another, we need to make a curve. That’s why modern armscyes are shaped like odd flatty eggs. When you look at armscyes in the 1500s, they’re a lot less complex. When you look through the patterns in PoF1, you’ll see the armscyes don’t have a lot of curving above the chest – they’re sort of an angled teardrop shape. That’s great news, because it means that once you have the strap at the right angle to the body, you’re only dealing with straight pieces. It hasn’t gotten near as complex as it will!
Hey, i am doing textiles at school and am trying to find a simple medievel dress pattern that wont be too difficult but i could get a good mark on. Can you help please? Thanks :)
Hi, Ellie – That’s something I’ll be getting to, yes, but it’s not planned for any time in the next couple weeks. You might want to check your local sewing store pattern section – look under costumes in the pattern books. Hope that helps….
[…] that I’ve got all the photography done, it’s time to pick up where we left off in The Basic Conical Torso Block (Part 1). We’re completing a basic torso block that we can use for the simplified, conical torsos […]
[…] version of the Conical Draft directions, and is probably much more useful if you’ve read the full version. It’s available below, and always available in the Downloads […]
This is seriously amazing! I now know what my next project is going to be :D. Thanks for your lovely words and inspiration, it’s so nice to read something that is well thought out, concise and clear in instructions. Being a maths nut is awesome as well!
I am NO mathematician and am struggling with some of your instructions.
On page two under Modeling the Body’s Curves…
1. My bust is 38″ and my waist is 40″ (I have a belly pooch). My front bust is 18″ and my front waist is 20″. I don’t understand what I’m subtracting. What would my Front or Back Triangle Bases be?
***Could you provide your doll’s measurements for examples?
2. Also, which line is the “midline” to mark the ticks from? The first line from the side measurement or the 2nd line from the side measurement? Meaning…is the midline the halfway mark from your front bust or is it a quarter of it?
Sorry about the confusion! Last thing’s first:
***You don’t want the doll’s measurements. I’m working in convenient 16ths of inches. It’s the ick!
2. The “midline” to use for marking the triangles is the vertical line that separates the front (or back) in half (drawn in the first two pictures on page 2). The only time you’d have more than one line dividing your front is in the adjustment for a very large bust/tum – I don’t think you need to take that step.
1. Since your waist measurements is larger than your bust measurement, you will be taking out along your bust line. Your front bust is 2″ smaller than your front waist. Divide that difference in half (because we’re only drawing half the front), and you have 1″. We’re going to divide that measurement into thirds, because we’ll be using it in three places: both sides of the front midline, and the front side of the sideline (first vertical line you drew). This gives you 1/3″, which is probably not on your ruler – it’s a hair more than 5/16″, which probably is.
So, along the bust line, mark a tick 5/16″ to the front of the sideline, and two more to either side of the midline. Draw a line that connects the sideline tick down to the waist/sideline intersection. Draw two more lines, one from each midline tick on the bustline down to the midline/waist intersection. You will have one nice looking upside-down triangle centered over the midline, and an upside-down right triangle at your sideline.
A little clever math tells me that your back bust and waist are the same. No adjustment is needed. You win, and don’t have to make any more ticks and triangles!
I hope that helps… If it doesn’t, email me directly and I can send you a picture of what I mean.
YES! I get it now! Thank you again!
I can’t wait to work on it tonite when I get home from drudgery at work.
PS – Do you have a facebook page? I’d love to friend you.
Yay! I’m so glad. :) And yes, I do have a facebook page – look for Melissa Heischberg. (I think I’m still the only one, and I’m pretty sure I managed to tell fb about my sebsite so that should help if I’m not.) I love having friends! :) I’m like, the worst fb friend ever, though – the facebooker and I don’t get on so well and I don’t log in a lot. Years of working in technology behind me, and somehow facebook still makes me feel like a techno-troglodyte. Go fig….
I’ve been struggling with this for days. 4 drafts and alterations later and I’m no closer to fixing whatever the heck I did wrong.
I am an hourglass shape who’s pretty busty so I followed those instructions. I’ve double checked my measurements and no matter what I do, I can’t seem to get it to close. It closes at the top, but not the bottom. Help! Please?
BTW I am totally in love with your website.
I’m so sorry! I don’t want to be adding to your frustrations! I’d like to help, but I don’t have enough information to tell you exactly what’s up. Here are some places to start:
1) Is the waist line staying true to your actual waist with no dips above or below at the center front/back? The number one reason why you’d see the waist not fit even though the measurement is right is because the waist line is off true – when it rises or dips, it’s going to be short because an angled oval cross-cut of the body will have a larger circumference than a straight cross-cut. It’s enlarged sort of like a long shadow. This can be caused by a number of things, but taking out triangles that are slightly off along the waist will do it, as will having the wrong bust-to-waist or armscye-to-wast measurements. I usually go back and check with a ruler to make sure that the finished waist line I got was the one I was going for, because numbers and I don’t get on so well. ;)
2) Are you leaving an extension at the Center Front when you fit, or are you cutting both sides to the marked Center line? The idea of the extension is that if the fit is off by a small amount (less than 2″), you can use the extension to mark the extra amount needed to close. You’ll then divide that extra wedge evenly and apply it to both fronts.
3) Is the draft extending significantly above the widest part of the bust? Sometimes boobs are like icebergs – there’s a lot more under the water (or bodice) line than you expect. If your bosom is sort of equally large around a large amount of the cup, it’s going to throw things a little bit – your draft has already started angling in to your waist, but your body itself is still busy being a bust. If so, you’re going to be a very good candidate for a curved front corset. Um, I’m not sure I know how to explain that in the space of a comment and without visual aids. As a basic example, if your front bust is, like, 22″ and your bust to waist is, say, 10″, and you check your front bust again 8″ above your waist and it’s *still* 22″, you fit into this category. The basic alteration goes like this: mark the top of the angled line from the front waist tick position to a point 8″ up the front line. This leaves you with 2″ of center front that have no decrease, to accomodate the particular shape of your bosom. (Realistically, this issue is shared by most women at a DD cup and above, so you’re not alone.) From there, the line comes in sharply to meet your waist and support the bust by compressing it underneath. Now, this is obviously not a curve, therefore not yet a curved front corset. You need to shave that angle below the bust into a curve – draw this to the inside of the two lines, rather than the outside.
Hopefully, some of that is at least as clear as mud. If it’s not, you can email me (missa at sempstress dot org) with the measurements you’re working with maybe a picture of what’s happening? I might be able to be more helpful then!
I’m so glad you like the site even though the draft is not working for you!
Thank you for this useful pattern.
I’ve red a month ago (but I don’t remember the right post) that you were going to do a pattern for a bodice attached to an open front over skirt: am I babbling?
Because I need it, but I am not able to find it.
P.S. Please, be patient with my english: I’m italian.
You’re not babbling! I just haven’t done it yet. Mea culpa! Here’s the easy way, if you know how to make a bodice and a basic pleated skirt (flat pleats or cartridge pleats, it doesn’t matter):
1) Make up a front opening bodice. It should be lined, because it has to support the weight of the skirts.
2) Make up a skirt with at least two panels. Instead of sewing the panels into a tube like you normally do, finish them as a very wide rectangle. The two “ends” of the rectangle are the front edges of the skirt.
3) Pleat the top edge of the skirt down to the size of the bottom edge of the bodice. (Cartridge pleats are good here, because it’s easier to adjust the size of the skirt!)
4) Instead of attaching the skirt to a waistband, attach it to the bottom of the bodice on the outside. Do this by hand with a sturdy thread. I usually place the top of the pleats about a half inch above the bottom of the bodice.
It’s a little more complicated if the bodice has a V to the waistline in front. Folding the skirt down to the inside so that if follows the line of the bodice works pretty well, and is arguable a period way to handle the situation.
Hope that helps a little!
Thank you very much for your answer!It’s been very kind of you.
I guess that sewing the skirt to the bodice is going to be the most difficult part.
I have just one dubt about the underskirt: if the overskirt has Cartidge pleats, the underskirt has to be that way too, to look good? But maybe two layers of Cartidge pleats it’s too much: I don’t know if all that tissue at the waist is going to look pretty…
Anyway, your site is great: it makes me wish I were a better sewer!
Usually when I do a cartridge pleated overskirt, I used a flat pleat for the underskirt. It’s hard to get two layers of cartridge pleats to sit correctly on top of each other. (You need to stagger them so they sit one on top of the other, rather than overlapping.)
I’m so glad you’re enjoying the site! :)
Your description is well detailed, I was almost able to do on the first go and I am pretty sure I can make it perfect…….
If you have a pretty wide shoulder measurement that ends up significantly larger in proportion to the bust, how does the math work out for that to make sure the armscye is not too narrow on the block? As it stands, half of my front and back shoulder measurements puts me within an inch of the side line, and I am playing with it now but it’s a little like shooting in the dark.
Could you please email me privately at missa(at)Sempstress(dot)org? I have a feeling that something has gone odd in the early part of the process.
Is this a set of instructions that would benefit from scripting? (I’m waiting for Le Moulage to come and so at a pause. )
Hi, Lucia – I’m sure there would be a few takers if there was a “no rulers” approach to this, but it is relatively simplistic so I’m not sure how many. It’d be fun to see it in action, though. ;)
Ok. I think I get get something out. It won’t have directions… but it will be great for feedback on features!
A link-back should do for directions for now. When you’ve got it up and running I’ll post a link to it!
I’ve started coding using Joseph Armstrong measurements for size 12 as a baseline. (The entry form will be last.) I’m at a stopping point here:
“Complete the armscye by drawing a U-shaped curve that connects the these two new lines. The curve should pass through the Armscye tick, but should never go lower. It may be asymmetrical.”
How high should I make the two sides of the ‘U’? I see you went up higher on the front than the back. I can put in any old thing to finish coding. By eye I would probably just try to do something I thought “looked nice” or “looked comfy”. But I figure a guideline would be nice.
Seeing as that the draft relies on a very scientific “then fold to fit” system with the straps, making them longer is better than making them shorter. That part is finished on the body.
On the folding: I rotated all the darts shut (so…. did the ‘origami’ in code) I control the length of the straps separately from the region that is part of the “U”. So, basically the armscye has a front and back curve.
* starts at the armpit/closed-side-dart location. Then it curves to right and up to a point that I deem the “top of the U on the front”. Then from that point, I go ‘up’ to make straps. I arbitrarily made these 5″ above the bust. (I could pick a body dimension, I just didn’t yet.) My question is really the where you might put the ‘top of the U on the front’. (I picked a value by fiddling. I happened to pick 4″.)
The back does a similar thing, starting at the armpit/closed-side-dart location, curving to the left and up to a point I call “top of the U on the back” which I made 3″. I made this smaller than on the front because that’s the way yours looks.
It’s these 3″ and 4″ I was wondering more about. Since you code, they are set like this with values corresponding to the 3 and 4 below.
So… obviously, nothing fancy was done. But I thought it would be best to set $armScyeCurveBack and $armScyeCurveFront to something based on a body or draft dimension. Obviously, all of these would be wrong for your doll.
Then, above that, I drew straps. Those are controlled with:
$strapLength at it’s current value puts the top of the strap 5″ above the top of the bustline. (Obviously, a user can extend those if they want to adjust as they sew).
For interpreting the figure: There is no legend– but generally, ‘blue’ is a seam line. Black is a ‘cutting line’ (except when it’s a dart that has been rotated closed. Ordinarily, I would just not show those, but I thought you might like something to indicate where they used to be. Note that the program does ‘not pretty things’ at corners leaving gaps or overlapping depending on whether the angle is obtuse or acute.)
These kinda-sorta use the Joseph-Armstrong size 12 measurements, but I had to substitute shoulder widths because she measures something on a diagonal instead of across the shoulders. So I suspect this looks like it’s for a somewhat broad-shouldered size 12 (possibly to the point of ridiculousness. Notice the distance between the back shoulder and the side seam is pretty small).
I haven’t coded the “full bust” adaptation entirely. It’s partly in there. But I plan to make a user interface tomorrow so people can put in their own measurements. There needs to be a “pdf” button too. That would permit people to first view an image an later get their PDF.
Oh– also, since part of your motivation is teaching it would be perfectly easy to create a png showing ‘pre-origami/rotation’ and ‘post-origami-rotation’. I just wanted to pick one or the other for now.
Do you have a link where I can see either the picture or the code we’re talking about?
If you’re using the Armstrong measurements, don’t use the F/B cross shoulders – use cross front and cross back. They’re taken on the straight of the body and will define the frame you need. For strap length, grab the F/B figure length measures, the subtract the length of the bodice – it will come out a little long since they’re taken at the neck, but that’s really better than short.
Oppps! The image
FWIW: I did indeed use F/B cross shoulders. I knew they would be too big… but I wasn’t sure if the alternative might not be too small. So I figured it was better to get a script running and collect together questions after the first go. Especially as in some cases I suspect I’ll find the answer if I read all pages more carefully. For example: right now I have the grainline down the center back. I have no idea whether that’s what you would do, but I’ll be re-reading next, tweaking and then writing the user interface tomorrow. Sometimes it’s best to ‘do it right’ at the outset… sometimes, it’s just as easy to put in a number and fix it later.
When you see the image, you’ll see how broadshoulders the ‘gal’ who would wear this looks. Possibly she is a guy with implants. . .
Ok, looking at it, yes, that’s a very wide shoulder – use the F/B cross measurements. That should straighten out the fact that that is a very wee teensy space left for the arm. I’m deeply suspicious of the curve in the waist as well – I feel like it should be doing more than that. I’ll take a look at the measurements in Armstrong as soon as I finish my Finance homework (which might mean Sunday *grumble* worstclassEVER).
I was looking at Armstrong. The remember a problem and it turns out to be a large contribution to ‘the’ wide shoulder problem. Obviously, her measurements don’t correspond to the same thing you picked to measure which merely means ‘adapt’. But going to ask you this.
In Armstrong size 12:
Back_Arc = 9 3/8
So in Armstrong,
2 *( Bust Arc+Back Arc) != Bust.
Now this is explicable as her instructions have bust and back measured to different elevations at the side seam. Bust arc is measured 2″ below armplate at side seam, Back Arc is measured at armplate at sideseam.
Reading yours I assumed for your draft, we want back arc measured at the same location as Bust Arc and used (Bust/2 -Bust_Arc)= Back_Arc_for_draft. That way the distance around the bust is the Bust measurement. But you can see that results in my using Back_Arc_for_draft = 18 6/8 -10 1/8 = 8 5/8 which is less than 9 3/8. After that, using the “across_back” or “across_shoulder” measurements both of which are 7 13/16 ends up with shoulders ridiculously near the side seam on the back draft.
On the one hand, the ultimate goal is to have people measure themselves so this would ‘fix’ itself when they take correct measurements following your instructions. But on the other hand, I would like to have the page load with some default measurements. To do something ‘quick’ it’s quicker to just use Back_Arc = 9 3/8 for the ‘demo’ (in which case, the width of the paper at the bust will end up 39″ for the what I’m ‘claiming’ is a ’12’. )
I’ll proof read the waist/ bust and the darts formed. If it looks suspicious, it probably is wrong. Maybe I screwed up a factor of 2 is a difference somewhere. Having debugged other things, common factors to be off are: 2, square_root(2) and π. Armstrong’s arcs tend to be 1/2 yours and if I went through quickly, I could easily confuse the two. Happens. There’s a pretty good chance I’ll have that checked tomorrow!
Heh… I just screwed something up. But yes, I had a factor of 2 wrong for the size of the darts. When coding I didn’t account for Armstrong’s arc being from center to side rather than side to side.
I’ve posted an image of the ‘default’ here. http://luciasews.com/2014/06/conical-bodice-generator/ Maybe you can have a look and see if you notice anything obviously wrong. The factor of two issue in the darts turned out to be a factor of 4! It’s fixed.
I plan to make a user interface tonight or tomorrow. (I also plan to change the defaults away from this ‘chesty’ woman!)
Left a comment with my thoughts on your blog.
[…] (of sorts) of stays of Eleonora de Toledo, (1562). For starting the process I relied heavily on semptress.org and created a paper pattern or “block” based on my measurement. Not to put too fine a […]
Learning to sew and create my own clothing has been a dream of mine since I was little that I’ve put off for decades. I’ve taken two short continuing education courses at FIT and most recently a one-on-one sewing class that was heavy on the pattern making while I was overseas for three months. I’ve gotten so frustrated because I’m still so confused and have yet to make anything on my own. I decided to purchase a machine and I’m getting familiar with the settings and getting comfortable with it. I figure the best way to learn is to just dive in without fear of making mistakes. I stumbled upon your website trying to find instructions on how draft a pattern for a top I have in mind that’s essentially a wench-y bodice (actually, I owned the top in mind but it fit horribly and my boobs would literally spill out if I moved an inch). Didn’t think I’d find one so I’m so glad I found this site. From what I’ve read so far, your instructions are thorough, easy to follow, clear, and actually enjoyable to read. It’s quite late so I definitely don’t have the attention span to get on this right now but im going to start the drafting the pattern tomorrow. thanks so much for sharing your extensive knowledge. How did you learn how to sew and draft patterns? Do you have any other tutorials for more modern pieces?
Hi, Nicole- so glad that this might help you! Jumping in and doing is definitely the best way to learn sewing and pattern drafting. Books are great and will help (a lot!), but no amount of reading will get the knowledge into your hands the way actually making things will.
I spent years and years trying and experimenting before getting an AAS in fashion design. Then I was lucky enough to work in a professional costume shop, then to teach in fashion design. This tutorial is actually something I developed for my students to try to make it easier to make custom slopers. (It was only partly successful in the classroom, sadly.) There are some more modern manipulations in the For My Students section of the site. I should prolly rename -lol. This site could use a few more modern or cute vintage drafts. It’s something I’ve been meaning to work on for a while.
Best of luck with your future sewing and drafting! Please reach out if things go weird. :)
Just realized I lied – I didn’t write this one for students. I wrote the math less draft for students. If you can find a helper (or you are seriously double jointed) that one might be a solid starting point for modern clothing!