July 17, 2016

Cloning a Seamless Cup

It can be very rewarding to clone a bra you love from RTW (ready-to-wear). You already know it fits and cloning it can save you time and money if you can get the fit on the first try. But what happens if you lay out your beloved seamless foam bra and the cup won't lie flat, even with the wire removed?

That means your cup has been molded at the factory and since you likely don't have a molding machine in your garage, you won't be able to duplicate this cup. Or can you? Actually, you can, as long as you are willing to have a seam in the foam. Let's see how to do it. First as I mentioned you have to remove the wire. I measured it against my set of wires and found it to be a 42 regular wire.
Place some see-through drafting paper on a foam core board. You'll also need some pins with heads on them (otherwise they hurt your fingers!) We are going to pin the parts of this bra out to their "pre-sewn" flat shape. In other words, how it looked right before someone picked it up to sew it.

Notice the seam that is at the middle of the bottom of the cup. That's where the seam ends between the back band and the front frame. Usually the seam is more toward the back but in the bra, it is directly under the cup as you might be able to see here. You can feel it as a raised bump along the bottom of the wire line.
We can start by pinning out the back band. I pin on the seamlines (where one fabric joins to another), and all around the outer edges. In the case of pinning lace, I only pin along the deepest valley of the lace and make a (more or less) straight edge.

Once the piece is pinned, I go around the edge with a larger pin (a hat pin or a floral pin is really ideal) to punch the pin marks and leave a nice hole in the paper that you will be able to see once the pins are removed. Then I "sketch" the shape from pinhole to pinhole. Don't try to be perfect at this stage - you just want to create a pencil outline you can see. I also marked the DoGS.
Pin out the bridge. If you removed one wire, make sure you only pin out half the bridge as the second wire will distort the shape of the bridge somewhat. better to pin out half and make the second half an exact mirror image.
Once I finish the band and front frame, it's time for the cups.  I need to find the apex of the cup. Not easy since there's no seam to guide you. Lay the bra on the table and get down at eye level to the bump of the cup. Using a fine pin, move the pin across the cup until it reaches the apex (high point) of the cup, or just until you cannot see the pin anymore. Put a pin there just catching the threads of the cup.
Next, turn the cup a quarter turn and repeat the process. You should have two pins that intersect at the apex.
Now you can decide what style line you want - diagonal, horizontal or vertical.  I folded the cup making sure the fold touches the apex pins and make the cup lie as flat as you can. If there are big bumps you cannot get out, either:

1. you may not have found the apex. The cup should lie flat if the pins are right at the apex.
2. you may have to divide your cup into more than two parts. The more seams you have, the more shaping you can have in your cup. This happens more often on the larger cups or the Omega shaped cups. Seams are your friend!

First I tried a diagonal seam. A diagonal seam starts in the underarm seam, runs through the apex and ends in the wire line seam. Here's what the lower cup would look like in a diagonal cup.

And the upper cup. It's ok, but not really the look I was going for.
The horizontal is not going to work at all. This cup is fairly low in the front and the horizontal seam would end up cutting across the neckline edge. Not a good look as you can see here. Forget that one.
Here's a vertical seam and I chose to run it from just to the inside of the strap running downward. Ah...much better. Here's the shape of the outer cup.
And here's the inner cup...looks good
Now you can pin along the fold to keep the two parts from shifting around. Then pin in the well of the seam to get the shape of the outer cup
And flip the cup to pin around the inner cup. it's actually quite easy!
After all the parts are pinned out and sketched, they should look something like this
Time to true the seams. Make sure the seams that are going to be sewn together match in length and the curves look smooth. This little seam at the bottom cup gets a thumbs up!
Continue until all the seams are trued up. This is where art meets engineering. If two seams are not the same length, I tend to lengthen the shorter one unless the longer one looks weird when I put the two together.
So here I raise the height of the back band. It is quite possible that I didn't pull the back band quite enough when I pinned it out. The back band stretches and the wire line does not, so I am trusting the wire line to be the more accurate of the two.
Finally I make the bridge into a piece I can cut on the fold at the centre front.
Now that I have my seamless bra cloned, I will sew it up out of similar fabrics. In this case, cut & sew foam will be perfect for this bra. I'm even thinking of duplicating these straps.
They have strap elastic, with narrow lace edging along the strap with the raw edge of the lace tucked in behind some fold-over binding. Very interesting! You can see the strap elastic underneath.
Here's the finished bra. In the end, we chose an off-set vertical seam for the client and a peach lace to cover the foam lining. We used fold-over binding along the neckline edge.
So that's how you clone a seamless cup bra. Now tell me...have you tackled cloning yet?


  1. I am a bit confused about the end product. Did you do the cut and sew foam as a vertical seam, and then do different seams on the cover? The cover looks like it has a diagonal seam to split the upper and lower cups and the lower cup has 2 seams. Or, was it just the shape of the original cup you were cloning?
    I love the peach bra!

  2. Thank you so much for this post! Since you remove the wire, I guess you are using only bras that you don't intend to use any more, or don't mind sacrificing? Or is there a way to insert the wire back and make it a usable bra again? Thank you.

    1. No, we put the wires back in the bra once we were finished. The client did not want to lose this bra - it's her favourite!

  3. Thank you so much for this tutorial. Now I can try to clone my daughters 34F cup bra.

    1. Let us know once you get it done! I'd love to see pictures!