How to draft new bra CUP designs with the Merckwaerdigh e-course

The most important task for the cup is not only to support the soft breast tissue but also shaping it. For this task 4 vertices are very important; they create an invisible diamond as it were, that pulls the cup in place. These vertices should be in good balance in all alterations of the cup master pattern :

midfront in between the cups
At midfront both cups come together. At this spot the cup can be higher or lower or even even rise above the band a bit when only the band is lower at midfront.
straps connection
The straps pull the cup up. This connection can be higher, lower or more to the side. Do NOT relocate this corner toward midfront because straps will always slide to the little dimple halfway the shoulder and this would make the cup unstable.
You can’t relocate the armpit, it has a fixed location. At this spot both cup and band should always fall equal.
midunder the cup
In the master pattern the vertical coupe line ends here. You can change the direction of the coupe line to create a horizontal or a diagonal coupe line. However, the lower part of the cup always needs to keep all the right proportions.


• Balance in the right fit
When there is a good balance between the 4 vertices of the ‘invisible diamond’ the cups will fall smoothly around the breasts. Whenever a design diverges on these vertices you can usually compensate this at another vertex of this ‘invisible diamond’.
• Balance in size
Basically in the master pattern the coupe line divides the cup in 2 equally sized parts. If your alterations ends up in a lot of size difference this will give the impression the breasts themselves are not equal. First create these 2 parts by drawing a new coupe line. Next you can add extra seams if you like (such as an extra seam in the under cup).

In the last posts I described the basic alterations for the bra band in the Merckwaerdigh master pattern. But what are the basic alterations for the cup?
They are the first steps for any new cup design and you deceide on them step-by-step when starting up a new design :

STEP 1 : drop or raise the cup midfront.
STEP 2 : relocate the straps, this will also affect the armhole and the cup top edge.
STEP 3 : shift the vertical coupe line into a horizontal or diagonal coupe line.

Though these are considered basic alterations it unfortunately doesn’t mean this will be easy tasks! Just like drafting the master pattern every step in this process is a laborious and meticulous job which takes considerable time and effort.
In bra drafting every mm counts!

All you need to do for the options within the 3 basic alteration steps will be fully described in the new Merckwaerdigh e-course I’m working on!
And a lot of tips as well like :
Sewing a QUICK TEST CUP from interlining fleece.
Personally I’m a huge fan of using interlining fleece when I’m drafting lingerie patterns. It’s great material for a quick 3D test of what I’ve actually drawn without having to sew a complete bra for a first impression.

When would you use a quick test cup?
• Testing a new coupe line; does it really have the curve I had in mind?
• Testing the proportions; are they still accurate?
• Testing the straps; are they not too high, not to low, not too much at the side?

Interlining fleece is kind of a combination of flexible fabric and paper, it’s the ideal material for this purpose :
• it doesn’t stretch
• you can sew it just like fabric
• you can write on it just like paper
• it’s even a bit transparant

No need to first trace the pattern on paper and then cut it from interlining fleece, you can trace the pattern directly on the interlining fleece because it’s enough transparant. You can easyly write all your information on each cup like which design it is, the date and size, how many tests you made. These are exactly the things you will quickly forget but maybe lateron might need. For example when you find a lost test cup on the floor … this happens to every lingerie seamstress from time to time!

It’s best to use a regular quality that still is a bit transparant and firm enough to keep shape by itself. You could also use Swedish Tracing Paper, comparable to interlining fleece and online for sale.
Only add a seam allowance on the interlining fleece at the coupe seam because you will actually stitch this for your quick test. Don’t add a seam allowance around the whole cup because this will make the cup look bigger than it actually is.

Next time we’ll get into alterations for STEP 1 at midfront in the front cup of the master pattern!

In the meantime ; since 8th of June 2020 the e-course is READY and available in the Merckwaerdigh shop on the Etsy platform!

For an overview of all the Merckwaerdigh internet activities and the button to subcribe to the Merckwaerdigh Newsletter take a look at


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