Saturday, March 19, 2011

Making a Swimsuit - Constructing the Top

Welcome back to the blogodyssey that has become the Making a Swimsuit series. When last I left you, I had reviewed a few options for bust support after making a trial version of my tankini top and realizing it needed more support and I hated the back.

Today, I will outline in detail how I constructed the top to my orange and white polka dot tankini.

As a reminder, I used two Kwik-Sew patterns for a jumping off point - Kwik-Sew 3779 and 3608. I loved the styling of 3779 but I hate one-piece swimsuits so I borrowed the bottoms from 3608, which is a tankini pattern.

If you're going to make a Kwik-Sew pattern exactly as it is pictured, just follow their directions as I found them to be super. The construction order I'm using is slightly altered to accomodate my suit being two pieces with a different back design. Alrighty, here we go.

First, I basted the two sides of the midsection fashion fabric, gathering the sides to match the length of my lining fabric. I have found gathering swimsuit material and then stitching it onto another piece of fabric to be the absolute trickiest part of sewing a swimsuit! Those gathers want to flatten out as you sew. So, I pinned them well and then basted the lining and fashion fabric together with zig-zag stitches, pushing the gathers under the needle in an orderly fashion with a needle.

I wanted lots of shaping in the bust cups, so I then installed my swimsuit cups. I situated the cups for placement, then pinned and zig-zagged the cups around the lining fabric.

I attached the lining/cups to the bust pieces by serging all edges together, forming one piece.

I cut a piece of clear elastic two inches shorter than the neckline edge and a piece two inches shorter than the armhole edge, and zigzagged that elastic to the serged edge, stretching as I sewed to ensure it fit from end to end.

I turned the clear elastic to the inside, and used a stretch double-needle with polyester thread in the needles and wooly nylon in my bobbin to top-stitch down the neckline edges on both sides. As you can see, on one side my stitching got a little wonky, but I'm ok with it.

I gathered under the bust cups and pinned the bust sections to the top of the midsection piece, ensuring the lining was caught into the seam as well. Zig-zagged the seam to lock in the gathering stitches and test for placement, then serged over that zig-zagging to clean up all exposed edges.

I measured a piece of clear elastic 1.5" shorter than the width of the midsection/bust seama and zig-zagged it onto the seam allowance of that seam, stretching to fit end to end.

I was now at the point where I had to decide what to do about the back - do I make halter straps that tie behind my neck, or bra-like straps that attach to the back of the tank? I think I've decided on halter straps; they have a slightly more retro feel that goes along well with the giant polka dots. I went with halter straps.

In order to finish the back and armholes before installing halter straps, I cut a piece of clear elastic 15" long and zigzagged it to the upper edge of the back fabric. In hindsight, I think I would cut it a little longer, maybe 15 1/2".

I then turned the entire edge (back and armhole run together), and used my double needle to topstitch the edge all the way around.

I made halter straps by cutting two 2" wide strips of fabric, about 12" long (I wasn't sure how long I'd need them to tie). I serged them right sides together, and then inserted a safety pin as a bodkin at the top of each bust strap, feeding that into the strap, stitching closed, and then turning the strap right sides together.

Now for the LAST STEP!!! Double-needle topstitch your hem at the bottom of the suit. That's it, your top is done!

Wow, those are some powerful bust cups, huh? Next time, I think I'll go with a more low-profile insert. Live and learn.

Stay tuned tomorrow, we'll make the bottoms and then wear this baby out in the sun!


  1. I really, really really want to make a swimsuit. I'm not totally sure what's holding me back, but something is. I think what it might be was that a few years back I was told that you couldn't make a swimsuit with fabric that had less than 15 to 20% lycra in it. I was having a tough time finding fabric like that, so I gave up. I might try again though.

  2. I really, really ......yes, me too!! I even started on my bathing suit (yes, that's right, no experience whatsoever with knits, elastic, bra cups, etc.) a few months ago and stopped before even finishing cutting it out. Not to mention that I'm totally intimidated/paralyzed in my sewing (yes me, the one who when she was 14 years old -over 40 years ago- actually sewed herself a suit (jacket, skirt and culottes) by sticking to it, following the pattern, until she did it, and kept on sewing totally alone (yes, I did take HomeEc when I was 12 & did learn about following a pattern) from patterns for some years with success), but have hardly sewn for decades now and have been lurking online for 2 years, addicted to watching what others are sewing.
    Your blogging with photos I can enlarge and actually see the stitching (the elastic, the bra cups, etc.) is truly empowering.
    Thanking you for sharing,
    Lynda from Toronto
    (persevering on sewingpatternreview)

  3. Yes, thank you for posting your trials and errors! I've been gathering supplies to give this a try too. I'm tired of paying so much for a little bit of fabric and elastic that doesn't even fit the way I'd like! I'm especially interested in hearing your thoughts on the powerknit. I'm thinking of giving that a try.

  4. Great tutorial! I'm going to be making a tankini as my next project, and couldn't find a pattern exactly how I wanted it so will be altering another pattern as well. I love how you changed the ruching so that the front panel is gathered on the side not the front. That's the look I want! Do you have any tips for drafting that pattern piece? The pattern I am altering does not have any ruching. Thanks!

  5. Oh I do agree it looks much cuter with this back & halter straps!
    Thank you for all this help.

    20 years ago I made at least 5 people swimsuits. It was not about saving money but about getting fit & style for each person who asked. I don't have a clue why im so intimidated by the thoughts of re-learning again?

    I was searching for the video I learned from, back when the dinosaurs and I were young and fearless, and like the dinos the vhs instruction is pretty much gone. But then I found you. After 2 or 3 of your "lessons" I searched my patterns and pulled out 5 awesome vintage goodies and ordered spandex and nuclear power mesh for my... ah, saggy bits n pieces, and dare I say, when it comes, I just might be ready to lay that spandex down for a day and let it rest before surging up a fancy pants suit!

    Those patterns beg to be cut. You have inspired me to push myself! YOU ROCK!
    Mia in PA

  6. this blog has been so helpful! I'm ready to tackle my first swimsuit and this has included so many handy tips :)

  7. Beautiful job!!! I don't think the bust cups are too's just perhaps shocking if you're used to a more modest profile, but heck, if curves are attainable, enjoy them