The Basic Conical Torso Block (Part 1)

For several hundred years, beginning where the High Middle Ages met the Renaissance and continuing through the eve of the French Revolution, fashion treated the female torso as something of an inconvenience.  The breasts were flattened, first by bands of wool or linen, later by corsetry and boned bodices. The sides of the body were straightened and the tum controlled.  The torso became a conic shape.  In some decades, like the 1590s, 1690s, and 1780s, it’s a very long cone.  In others, like the 1640s, it’s a very short cone that disappears into skirts below the bust.  During these times, a very basic conical torso block can be used as a basis creating custom patterns.

You will need the following measurements:
  1. Waist, Front/Back Waist
  2. Nape to Waist Length, Nape to Bust Line Length
  3. Front/Back Shoulder to Shoulder Width
  4. Bust, Front/Back Bust
  5. Armscye to Waist

You will also need:

  • a Yardstick
  • a Pencil (or Pen, if you’re confident!)
  • Paper Scissors
  • a Large Sheet of Paper (old wrapping paper and brown paper bags cut and spread flat work well)
  • optional: a Calculator
  • optional: a French Curve (if you don’t like drawing curves
  • optional: Poster Board (for a quick and dirty mockup)
  • optional: Tape (I hate it, but I hear others can’t do without)

Overview and Goals

We’re going to be drafting a custom block to your measurements.  This block will serve as a starting point for many historical (and fantasy) bodices, corsets, and dresses.  This block will have no ease: that is to say, it will be made to your exact measurements, with nothing added and nothing taken away.  Most corsets and boned bodices use something called “negative ease”, where the garment is actually slightly smaller than the torso that gets smashed into it.  We’ll deal with the negative ease when we manipulate this block into patterns, but not now.  (Because different areas of history use different amounts of negative ease, taken out in different fashions.)  The point of this block is to ensure that all future patterns are based on something that fits.

This block has been designed to handle bodies where the front half of the body is larger than the back half.  (The bustline is a popular place for this to happen.)  It has also been designed to work for every body, not just the easy column shaped ones, by the use of a few extra measurements and a little origami.  (In other words, this is going to be a little more involved than the ultra-basic renaissance corset pattern you might be familiar with.)  Figures that are significantly asymmetrical due to scoliosis or a similar condition will need to make separate drafts for the left and right sides of the body, to reflect the difference in Armscye-to-Waist length and/or Shoulder-to-Shoulder distance that results from spinal curvature.

To the best of my knowledge, this is not a period-correct drafting technique. It’s based off of a simplified version of modern darts.  This is, however, a darned good place to start if you’d like to ultimately arrive at period patterns redrafted to your body without spending a huge amount of time begging people to help you pin things to you.  ;)

Beginning the Block

Start with a large sheet of paper.  It should be at least 1/2 of your Bust (or Waist, if larger) measurement wide by  your Nape-to-Waist measurement tall.  Larger is better, here, because finding out that you’re a half inch shy of the amount of paper you need for your draft is very annoying.  I’ve done it many a time…  We’ll begin by determining which is larger: Bust or Waist.  This will affect things later, so be aware of it now.

Please note: I am doing this draft to the size of a 16″ fashion doll.  It makes it way easier to get pictures of the draft, but her proportions are a little exaggerated and everything is going to look oddly miniature.  The method does not change, just the size of things….

On your large sheet of paper, we can start marking out lines:

Start by laying out an ordinal grid.

Start by laying out an ordinal grid.

Start the basic conic draft by laying out an ordinal grid: two lines that meet at right angles.  The vertical line will become the side line of the body (directly below the armscye), and the horizontal line will become the waist line.  I’ve labelled these, and labelled the Front and Back sides of the draft (with an F and B, respectively).

Now, subtract your Nape-to-Bust measurement from your Nape-to-Waist measurement.  The result is your Bust-to-Waist measurement.  (I know that sounds convoluted, but it’s based on how we took the measurements – which started at the nape of the neck.)

Mark in the Bust line.

Mark in the Bust line by measuring the Bust-to-Waist distance above the Waist line. The Bust line should be perpendicular to the Side line

At this point, you must decide if your Bust or Waist is larger.  I’m working with a Bust that is larger than the waist.  If you are working with the opposite, use the Waist measurement everywhere I use the Bust and the Bust measurement everywhere I use the Waist.  You’ll be drafting the same way, but your pictures will look upside-down to mine.

Measure 1/2 of the Front Bust measurement out from the Side line (to the Front side of the draft).  Make a line perpendicular to both Bust an Waist at this distance.

Measure 1/2 of the Front Bust measurement out from the Side line (to the Front side of the draft). Make a line perpendicular to both Bust an Waist at this distance.

Repeat, to the back side, using the Back Bust measurement.

Repeat, to the back side, using the Back Bust measurement.

At this point, you should have a clear idea of why we call these things ‘pattern blocks’.  We start by making a rectangle that describes the bouts of the largest part of our measurements.  Now we just chip away everything that’s not part of the pattern (much like the immortal, and entirely smarty-pants, instructions on how to carve an elephant from a block of ivory: start with a block, and carve away everything that isn’t part of an elephant.)
Next: Modeling curves…

40 thoughts on “The Basic Conical Torso Block (Part 1)

  1. The Basic Conical Torso Block (Part 2) | Sempstress says:

    […] 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 […]

    7 years ago | Reply

  2. Printer Friendly Version of Basic Conical Draft directions… | Sempstress says:

    […] 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 […]

    7 years ago | Reply

  3. missa says:

    Hey, Mo,
    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.

    6 years ago | Reply

  4. Monique says:

    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.

    6 years ago | Reply

  5. missa says:

    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….

    6 years ago | Reply

  6. missa says:

    Hi, Nat,

    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!

    6 years ago | Reply

  7. missa says:

    Hi, Giulia,
    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!

    6 years ago | Reply

  8. missa says:

    Hi, Giulia,
    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! :)

    6 years ago | Reply

  9. mastsethi says:

    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…….

    6 years ago | Reply

    • missa says:

      Hi, Katie,

      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.

      Thank you,

      4 years ago | Reply

  10. lucia liljegren (@lucialiljegren) says:

    Is this a set of instructions that would benefit from scripting? (I’m waiting for Le Moulage to come and so at a pause. )

    3 years ago | Reply

  11. lucia liljegren (@lucialiljegren) says:

    Ok. I think I get get something out. It won’t have directions… but it will be great for feedback on features!

    3 years ago | Reply

  12. lucia liljegren (@lucialiljegren) says:

    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.

    3 years ago | Reply

  13. lucia liljegren (@lucialiljegren) says:

    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.

    The front:
    * 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.

    3 years ago | Reply

  14. lucia liljegren (@lucialiljegren) says:

    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. . .

    3 years ago | Reply

  15. lucia liljegren (@lucialiljegren) says:

    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:
    Bust_Arc=10 1/8
    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!

    3 years ago | Reply

  16. lucia liljegren (@lucialiljegren) says:

    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.

    3 years ago | Reply

  17. lucia liljegren (@lucialiljegren) says:

    I’ve posted an image of the ‘default’ here. 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!)

    3 years ago | Reply

  18. corset … no I’m not wearing a corset, this happens to be a fitted gothic dress | dressedtess says:

    […] (of sorts) of stays of Eleonora de Toledo, (1562).  For starting the process I relied heavily on and created a paper pattern or “block” based on my measurement. Not to put too fine a […]

    3 years ago | Reply

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