Bra-Making Favourites: Cut and Sew Foam & and Fold Over Elastic!

Hi All! I’m Erin, or Emerald Erin, you might know me from my blog The Sewing and Life Adventures of Emerald Erin! I’m mostly a bra-maker or swimsuit sewist- but I like to dabble in lots of creative endeavours! You also might know me from my Bra-A-Week Challenge– where I sew a bra or swimsuit every week and post it on Sundays along with all of your lovely bra submissions! I’m also a full-time blogger, custom bra/swimwear maker, sewing instructor and pattern designer who is in the middle of launching a business!


I’m so excited to be here doing a guest post for Lingerie sewing month- especially since every month for me is lingerie sewing month! And I thought that I would share two of my favourite bra-making materials and how I like to sew them! First I’m going to start with cut & sew foam, also known as pre-finished foam padding, or polylaminate foam padding.

IMG_2213 If you’ve already worked with this foam then you’ll know that it is lovely! And it gives you the coverage and support of foam, but in your unique shape- unlike the molded foam cups! I’m going to show you how I like to sew it on this sample cup- remembering to cut out your pattern without the interior seam allowances- since you are going to butt your fabric together and sew it.

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Now this is my favourite way to sew seams in cut & sew foam. I like to use a ‘satin stitch’ because I find that it is the nicest and strongest finish.  And on my machine that is a simple zig-zag stitch with a 4 width and 0.5 stitch length. With that stitch I butt my pieces together and stitch them together.

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When you’re sewing them together, you’ll notice that this stitch almost squeezes your fabric together nice and tight- making it look like there isn’t a cut in the fabric in between. This stitch can take a little practice, and you want to make sure that you don’t have too heavy of pressure from your foot and your feed-dogs are moving the fabric through nicely to prevent any stretching in the seam- which you don’t want! Sometime it can even help to push it through a little bit. Now the alternatives that I’ve seen to this stitch are a regular length zig-zag (this sample one is 3 width by 3 length on my machine) or a 3 step zig-zag (this sample on is 4 width by 1.5 length on my machine). What I notice is that these stitches tend to leave more dimples and unevenness that will show through your outer fabric, rather than the satin stitch which looks a lot more even.

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The other important part is the strength- when you pull on all the seams, the regular and 3 step zig-zags tend to pull apart and make gaps, and the satin stitch stays strong and together!


So here you can see an example of a cup that I’ve made up with the satin stitch, and how smooth it is around the curves!

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It really makes for a nice cup! All of my every-day bras are made with this foam and this stitch and I find that it wears wonderfully and is nice and smooth and soft against the skin!


Now on to my second favourite bra-making material which is fold over elastic! or FOE for short!

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There are lots of different types of fold over elastic that you can get- different widths, shiny sides, matte sides, picot edge, pre-folded, flat. like working with this flat 3/8″ fold over elastic (3/8″ when folded) and I prefer the matte side to the shiny side. I like to sew on my fold over twice, because I’m not very good at keeping it sandwiched around my fabric, and I find that it’s easier and quicker to sew it on twice! For this I like to use a very small zig-zag stitch, which on my machine is a 1 length by 1 width (I have a thing about same length/width zig zags lol).

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I start with the wrong side of the fabric facing up and I line up the centre of the fold over (you can usually see the line where the centre break is) just on the outside of the edge of your fabric. Once you get sewing you can check to make sure it’s in the right place by lifting it up and lining it up just off the edge. You can also pin this if you like- but I find it just as easy to manoeuvre it as I go. Also I don’t like to pull on my elastic as I go- just keep it finger tight- so it’s not completely slack, but just a slight hint of tension.


I sew right on the edge of the fold over- being careful to stay on the fold over and not go over the edge into your fabric- because you’ll see that from the front if you do!  Then when you flip it over to the right side of your fabric you’ll see your stitching through- which is a good guide to follow when you stitch down your other side.

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You’ll also notice that you can see that centre break of your fold over elastic right over the top edge of your fabric- which means that when you fold it over it will be right where you intended your fabric edge to be- no taller, no shorter! If you’re working with foam, like I am in the example I would recommend trimming some on the fabric above your seam to reduce bulk- you won’t have to do this if you’re using a really light or lacy fabric.

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Then all you have to do is fold your elastic over where it naturally wants to fold along the centre line, you can pin it if you like, or not if you’re comfortable doing it with no pins. But the important thing is that you use your stitches from the other side as a guide and that you make sure to cover them with the elastic on the right side. Then you’re going to do the same stitch and sew right over top of your old stitching on the edge of your elastic. And voila!!


You have a beautifully finished edge with very minimal bulk! On the front it will have a single line of small stitching and on the back it will have an overlapping double line. And I find with this zig-zag that it has enough stretchability that I’ve never had it pop before. Here are some example of my foam and fold over projects- you can see it’s definitely a fav!

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This is a perfect example of the cut and sew foam cup with a satin-stitch and nice fold over elastic on the top- and you can see how it all just blends beautifully with matching threads! This is my bra from Week 8!

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This is an example of a fold over project that I did with a double strap- where I used fold over for the neckline edge and the underarm edge on a bralette and continued it up to straps. To make it a little more supportive I added some non-stretch ribbon on the inside of these straps and that added some good stability. This is my bralette from Week 9! I also use a similar technique with fold over binding- that I like to use for contrasting edges on my swimwear!


The possibilities with this are really endless and I keep finding new ways to apply it. This is my swimsuit from Week 18! Do you like working with cut&sew foam or fold over elastic? What are your favourite bra making materials? Also don’t forget to come over and check out my blog! I’ve got lots of fun things going on right now! You can join the Bra-A-Week challenge and be inspired by all the other lovely submissions! Or you can follow me on my bra and swimwear adventures!  I’ve recently gone into the bra and swimwear business full time! So you can join me as set up my new studio, launch my online store and figure out my creative business! Yay! Hope to see you over there!

xo erin