The Bra Sloper: Bare Essentials Bras 3rd Edition

In my previous post, I talked about creating a custom bra draft using the method from the book Bare Essentials Bras, 3rd edition by Jennifer Lynne Matthews-Fairbanks.  After finalizing the fit of the bra draft, the 3-piece cup, cradle and band are turned into a sloper to make custom bra designs.

What is a sloper?

A sloper, in fashion industry terms, is a basic building-block pattern without seam allowance or design lines.  It is used as a starting off point to create various designs.  For a bra, the sloper includes a basic cup, a cradle without bottom shaping and a back band. Here's a peek at my sloper, drafted in Adobe Illustrator.

So, what on earth are all the lines on the cup?

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The lines represent many different options for style lines.  I used a different colors to represent each category of lines: horizontal, vertical or diagonal.  

​After separating a cup into pieces, curves are added to the style lines to form to the shape of the breast, and a different amount is needed depending on whether the line is horizontal, vertical or diagonal.  The number of pieces in the cup also affects the amount added.  Luckily, Jennifer's bra calculator determines these amounts for you.  I need a higher percentage than what is indicated on her chart (which uses 2.5%), but it was helpful to see how the amounts relate to the number of cup pieces.  Below is the results for the cup curves in the bra calculator.  

How to use the sloper

It looks a bit confusing at first, but the book walks you through several design drafts to give you some confidence for creating your own designs using the sloper.

For my first design, I want a 2-piece cup with vertical seams.  I simply separated the cup on the vertical lines and added in the curves.  I have a lot of bottom fullness, so there is a higher percent added to the bottom of the cup than the top.  

The cradle/frame and band from my initial draft worked well, so I used those pieces again.

Here is my bra all made up in my custom pattern!  I'm a bit fluffier than my dress form, so the cups aren't quite filled out properly. But, amazingly, the cups fit me perfect on the first try! I wasn't sure they would, since I didn't quite know exactly how much curves to add.  The great thing about working with a well-fitting sloper is that any pattern made from it should only require a few tweaks to the fit. 

​More details about the materials and construction of the bra tomorrow.  Stay tuned!  Happy sewing.