- Written by Mark Garbarczyk
In this second part of this bra pattern drafting and making series we will be drafting (drawing) the blocks/patterns for the cups, cradle and wings of a simple under wired “Darted Cup” Bra. Think of this bra as your first test into the world of bra pattern drafting and making. It may not offer the best support for the fuller bust, but it will allow you to check your measurements and fit, particularly cup volume / shape and wing tension.
In this part, I will be screaming, “ACCURACY” ... NO cheating by “pin copying” or pulling your favourite bra apart!
This bra is the simplest bra to make as the cups only have one short dart seam to sew. The bra has underwires and it will be the shape of the underwire that you will use as the start of the cradle/wing pattern. This bra can also be made without any underwires, but the cup shaping and support may suffer in larger sizes. If you wish to make the bra without any wires, you will need to use a “Breast root trace” to give you the right curves to the bra cradle to fit you.
I know that the debate on underwires in bras is always a hot topic, but the correct sized, properly “sprung” underwires can do a good job of supporting the cup / cradle shape to support the breast weight, and until an alternative to the bra under wire comes along (I am still working on that one) we will try to work with them. (For people who have missed some attempts at alternatives to underwired bras, Charnos had a financial disaster with their “Bio Bra”, and Playtex have a non-underwire bra on sale at the moment that uses some sort of plastic “fingers” for the cup/breast support. Does anyone remember the “Magic Fingers” pattern Playtex sewed on the front panels of their girdles? They were supposed to help hold your tummy in, like the fingers on a pair of hands, or so the advert went).
We will come to “Breast root tracing” and “springing” a bra wire in a moment, but first we must get some drafting/drawing tools together.
If you have read Cathy Hay’s excellent articles on corset pattern drafting you may already have the right drawing equipment for the job, but I will give you the list of tools anyway.
“Flexi Curve” for drawing smooth free curves and for taking a “breast root trace”, and a set of “French Curves”
Taking a breast root trace using a Flexi curve (right)
Drafting a Bra Cup Block
We will start with the bra cup block (remember in industry, a pattern without seam allowances is called a Block). We will draft a Size 4 cup (about a UK size 34”B) and then grade (resize) it to your breast size. Remember, gentlemen who are following the articles, or those not making for a specific person: please use the Size 4 cup / 50cm back measurements, but please do try the cup grading.
TRY TO BE AS ACCURATE AS POSSIBLE. I have quoted the measurements to two decimal places. I know that one millimetre is a very small division on a ruler scale but try to judge the second decimal place number and keep your pencil / compass lead sharp. Use an emery board or nail file to sharpen the “lead” in your compasses.
Step Seven: Shift Grading
Copy the cup plus radial lines onto another sheet of stiff paper (photocopy or use a tracing wheel and carbon paper) and then cut the copy of the cup out. You will use this second cup to mark around on your original drawing as in the diagrams.
You now need to measure along each radial line (1 to 7) from the centre “Point of Bust” of the Size 4 cup you have drawn the right number of grading “steps” for your cup size, To save you time and your calculator batteries, I have given you the line lengths (1 to 7) you need to mark on your Size 4 cup lines in the table to grade the cup to your size. All measurements are taken from the centre Point of Bust point of the cup.
OVER BREAST MEASUREMENT
(All Measurements in cm) grading step = 1.7cm
|lower measurement||higher measurement||LINE 1 LENGTH (STEP 1.07cm)||LINE 2 LENGTH (STEP 0.85cm)||LINE 3 LENGTH (STEP 0.81)||LINE 4/5 LENGTH (STEP 0.76cm)||LINE 6 LENGTH (STEP 0.86cm)||LINE 7 LENGTH (STEP 0.98cm)|
|Cup Size1||14.1cm to 14.7cm||14.1||14.7||8.36||6.69||6.81||6.44||7.68||7.51|
|Cup Size2||15.8cm to 16.4cm||15.8||16.4||9.43||7.54||7.62||7.2||8.54||8.49|
|Cup Size3||17.5cm to 18.1cm||17.5||18.1||10.5||8.39||8.43||7.96||9.4||9.47|
|Cup Size4||19.2cm to 19.8cm||19.2||19.8||11.57||9.24||9.24||8.72||10.26||10.45|
|Cup Size5||20.9cm to 21.5cm||20.9||21.5||12.64||10.09||10.05||9.48||11.12||11.43|
|Cup Size6||22.6cm to 23.2cm||22.6||23.2||13.71||10.94||10.86||10.24||11.98||12.41|
|Cup Size7||24.3cm to 24.9cm||24.3||24.9||14.78||11.79||11.67||11||12.84||13.39|
|Cup Size8||26.0cm to 26.6cm||26||26.6||15.85||12.64||12.48||11.76||13.7||14.37|
|Cup Size9||27.7cm to 28.3cm||27.7||28.3||16.92||13.49||13.29||12.52||14.56||15.35|
|Cup Size10||29.4cm to 30.0cm||29.4||30||17.99||14.34||14.1||13.28||15.42||16.33|
|Cup Size11||31.1cm to 32.8cm||31.1||31.7||19.06||15.19||14.91||14.04||16.28||17.31|
|Cup Size12||32.8cm to 35.6cm||32.8||33.4||20.13||16.04||15.72||14.8||17.14||18.29|
|Cup Size13||34.5cm to 38.4cm||34.5||35.1||21.2||16.89||16.53||15.56||18||19.27|
|Cup Size14||36.2cm to 41.2cm||36.2||36.8||22.27||17.74||17.34||16.32||18.86||20.25|
|Cup Size15||37.9cm to 44.0cm||37.9||38.5||23.34||18.59||18.15||17.08||19.72||21.23|
|Cup Size16||39.6cm to 46.8cm||39.6||40.2||24.41||19.44||18.96||17.84||20.58||22.21|
|Cup Size17||41.3cm to 41.9cm||41.3||41.9||25.48||20.29||19.77||18.6||21.44||23.19|
|Cup Size18||43cm to 43.6cm||43||43.6||26.55||21.14||20.58||19.36||22.3||24.17|
|Cup Size19||44.7cm to 45.3cm||44.7||45.3||27.62||21.99||21.39||20.12||23.16||25.15|
|Cup Size20||46.4cm to 47cm||46.4||47||28.69||22.84||22.2||20.88||24.02||26.13|
|Cup Size21||48.1cm to 48.7cm||48.1||48.7||29.76||23.69||23.01||21.64||24.88||27.11|
|Cup Size22||49.8cm to 50.4cm||49.8||50.4||30.83||24.54||23.82||22.4||25.74||28.09|
|Cup Size23||51.5cm to 52.1cm||51.5||52.1||31.9||25.39||24.63||23.16||26.6||29.07|
|Cup Size24||53.2cm to 53.8cm||53.2||53.8||32.97||26.24||25.44||23.92||27.46||30.05|
|Cup Size25||54.9cm to 55.5cm||54.9||55.5||34.04||27.09||26.25||24.68||28.32||31.03|
|Cup Size26||56.6cm to 57.2cm||56.6||57.2||35.11||27.94||27.06||25.44||29.18||32.01|
|Cup Size27||58.3cm to 58.9cm||58.3||58.9||36.18||28.79||27.87||26.2||30.04||32.99|
|Cup Size28||60cm to 60.6cm||60||60.6||37.25||29.64||28.68||26.96||30.9||33.97|
|Cup Size29||61.7cm to 62.3cm||61.7||62.3||38.32||30.49||29.49||27.72||31.76||34.95|
Now using your Flexi Curve / French Curve, smoothly join up the “corners” to give you the new cup outline.
Copy the new “your size” cup onto another sheet of paper (photocopy or use a tracing wheel and carbon paper) and then cut the copy of the cup out. Using sticky tape, stick the cup “Dart” together and check the “look” of the cup. Do not worry that the cup comes to a point, paper will not “flow into shape” like fabric and when you sew the fabric cups you should sew outwards from the point of the dart to remove the “point”. When we come to adapt this cup to two and three panel bra cups we will have smoother over bust seams.
Drafting the Band
If all looks OK with the cup, we are now almost at the stage to start drafting the Cradle and Wings of the bra, but you need to find the correct curve for the Cradle to Cup seam.
As this Cradle to Cup seam is where the underwires will be sewn and it is the seam that sits up against your Breast Root, these are the two things that we will use to draft the length and curvature of the seam: a Breast Root Trace and an Underwire.
Breast Root Trace
To take a breast root trace, use a Flexi Curve and a sheet of paper.
Put the Flexi Curve around your breast (right breast as we are drafting the right half of the bra or you can trace your left breast and flip the trace over on the paper) and make sure it is up against the point around where your breast tissue joins the chest wall. This is the same point around the breast where the underwire of a correctly fitting bra should sit, not on breast tissue (pain) and not away from the breast (poor fit).
Now mark on the Flexi curve, with chalk or thin tape, the point directly (vertically) below the nipple or fullest part of the breast.
Next, imagine a horizontal line across the fullest part of the breast and put two marks on the Flexi Curve ether side of the breast and about 2cm above the imaginary horizontal line.
You may need the help of a close friend to do this while you hold the Flexi curve against yourself.
Now CAREFULLY take the Flexi Curve away from your breast without moving its curve and place it on the sheet of paper. Again carefully draw around the edge of the flexi curve that was up against your breast and transfer the three marks to the curve on the paper.
You now have a curve to help you find the correct underwires for your size and to draft the correct cup to cradle seam. Hurrah!! You just may be on the way to a bra that actually fits you.
Now you need to get hold of two underwires for your bra that match your breast root trace. If you are obtaining your wires in person from a shop you can take your breast root trace with you and try their wires against it. If you are planning to get your wires from the internet see if the company has “to size” drawings or pictures of the wires they sell, so you can again match up your trace to the correct wires.
An Internet company I use for corset and bra bits is www.sewingchest.co.uk; they have a downloadable PDF document that shows all the underwire sizes that they sell. You could try to find “MS20” underwires in your size, the MS20 underwire is a good “day bra” shape and it is the wire shape that the largest UK underwear retailer (clue: give us an "M"; give us an "S") have as their standard.
One major point: the wire that is closest to the size and shape of your breast root trace will veer away from the trace curve at the underarm side (right).
This is because when the wires are in the bra and worn, the wires are “pulled open” or “Sprung” to the curve of your breasts by the elastic pull of the wings of the bra.
So do not worry if you cannot find underwires that exactly match the curve of your trace.
Another tip: choose a “Day wear” underwire. Steer clear of “Plunge” underwires and “Strapless” styles at this stage.
Here is the shape of a typical Daywear wire for a UK 34”B bra which will work with the Size 4 cup, for readers who do not have “client” to make a bra for. Print the picture off and use it to obtain two underwires.
When you have got your wires, you can continue with the pattern drafting, or you can use your Breast root trace if you want to have a go at making the bra without any underwires.
The Cradle and Wings
We will draft one half of the bra and when we come to mark and cut out the fabric we will turn the pattern parts over to give us both halves.
Copy the Cradle (from CF to side seam) onto a new sheet of paper and copy the Wing (from side seam to hook & eye CB) on to a new sheet of paper.
Now add 5mm seam allowance to all three patterns (Cup, Cradle and Wing) plus cutting and sewing marks i.e. pattern name, number of parts to cut out, direction of fabric weave and seam alignment marks. There is NO seam allowance added to the Wing at CB (centre back) as the hook & eye tape wraps around the end of the wing.
The pattern instruction “Cut one pair” means we will cut out a left and a right side. So when we mark out the fabric we will mark out the right side of the bra parts then “flip” the patterns over and mark out the left side bra parts. We will not fold the fabric and try to mark / cut out a pair at one time! That way is “Home sewing": for accuracy in industry nothing is “cut on the fold” and we will not pin the patterns to the fabric.
But more of that next time...
Just what I need for a corset I have in mind :)
The method of drafting bra patterns that is available to me didn't give very good results. It was ill fitting and needed a lot of alternation...it looked like it wasn't made to measure at all but your way looks really promising and I will give it a go as soon as I get my coutil :D
Thank you for a wonderful easy to understand article!
Hi Mark, just a question re the drafting. When you spring the wire 1,5cm to the side, I found it lowered the height of the end of the wire, bringing it almost horizontally level with the centre front point on paper. Should I use this new end point to add the 8mm, or should I use the original end point "height" but 1,5cm to the left? In the diagrams, the height doesn't seem to change much in the the "springing". Thanks for any advice. Wendy
Hey I am trying to make a custom corset, got the coutil in and half of the fabric, I would like to add underwire support and I can calculate that into the pattern since it is already sized... Which of your cup sizes would you suggest for a UK 30FF? Oh and the design requires steel cable, but instead of 1/4" I plan on using 3/16" coated so the ribbing shows less and for easy removal so the thing can actually be washed. And do you believe springing would be an issue since it is a corset? I dont plan on buying underwires, just properly directing more cable. Length wont be an issue I have cutters so I will just get a bit more than necessary. Thank you for your time!
Just a note, take a breast root trace over the skin without a bra so you have a better feeling of were the breast tissue joins the chest wall. Keep your arms down and it helps to lean forward slightly so that the breasts hang away from the chest. If you do not have a flexie curve you can use any stiff wire that can be bent to your curves.
Corset Hugs, Mark
A big sorry for not responding sooner to your comments but until recently I have not been able to get my Internet computer to post comments on the website. I would not write the articles then totally ignore you, I am very interested in your feed back as it helps me as a designer / pattern drafter of bras, remember being male “I make purses but have no money to put in them” .
You do not say what your cup size is but I suspect you are a size 10 cup or above (classic modern English lady, large bust – small back). To do the wing draft, miss out step 9, draw the 32% line, 2.5cm, 4.8cm and the 6.6cm lines then draw a gentle curve (top wing hem line) from the top of the 6.6cm line to the top of wire curve at underarm. Mark along the curve the 9.3% BM, draw a straight line down from the 9.3% mark to the 4.56% mark. This will give you your Cradle to Wing side seam.