Sophie Swimsuit Pattern // Balconette cup swimsuit pattern with bikini and one-piece options // Closet Case Files
Closet Case Patterns


Happy first day of summer everyone! It’s like the season conspired to make this pattern launch as perfect as possible, because today I am thrilled/elated/stoked etc. etc. to introduce the newest Closet Case swimwear pattern, the Sophie Swimsuit!!!

This pattern has been in the works for over a year. I had started sketching ideas and making plans for a cupped, underwired swimsuit when my homegirl Sophie over at Ada Spragg wrote a post bemoaning the lack of one in the pattern world, and I laughed to myself and said, “Well Sophie, you just got a pattern named after you”. Can you think of a more glamorous or stylish pattern muse? YEAH ME NEITHER.

Sophie Swimsuit pattern_One piece bustier suit

This pattern has definitely been my biggest labour of love yet. Turns out designing the ultimate swimsuit isn’t easy, but I couldn’t be happier with the end result. Here are the details:

With curvy seam lines and a 3-piece balconette cup, Sophie is both va-va-voom flattering and reassuringly supportive, a silhouette equally appropriate in the south of France or the neighborhood pool.

View A is a classic one-piece with a pronounced hourglass shape and skinny elastic straps. View B mixes a bra-style halter tied top with an elegant high waisted bikini bottom. With a low cut leg and a full cup, both offer sexily modest coverage. Tap into your inner designer by playing with contrast fabric and colour blocking, and learn how to add optional underwires and foam cups to make the most supportive swimsuit ever!

View A has an iconic bustier look and I love it with a colour blocked body – it really highlights that curvy hourglass center panel.

Sophie Swimsuit Pattern// Foam cup underwired bustier style one piece // Closet Case Files Sophie Swimsuit Pattern// Foam cup underwired bustier style one piece // Closet Case Files Sophie Swimsuit Pattern// Foam cup underwired bustier style one piece // Closet Case Files

View B is a very supportive bikini top with a properly high waisted bottom. We’ve paired the top with a soft fabric halter strap but you can easily interchange the elastic bikini straps as well.

Sophie Swimsuit Pattern// Foam cup underwired bikini top + High waisted bikini bottom // Closet Case Files Sophie Swimsuit Pattern// Foam cup underwired bikini top + High waisted bikini bottom // Closet Case FilesSophie Swimsuit Pattern// Foam cup underwired bikini top + High waisted bikini bottom // Closet Case Files Sophie Swimsuit Pattern// Foam cup underwired bikini top + High waisted bikini bottom // Closet Case Files

My favourite detail of this pattern is the cup shape. We worked really hard to get a good fit here; it ended up changing quite a bit during testing based on everyone’s feedback but I think we found a really flattering shape (shout out to the best pattern testers ever! xoxoxo).Sophie Swimsuit Pattern// Foam cup underwired bikini top + High waisted bikini bottom // Closet Case Files

Please note that this release is PDF only; because the pattern is massive with 55 sizes (each of our  typical 11 sizes comes with 5 cup sizes) it quickly became clear that it would be impossible to go to print. However, each size is broken down individually by View, so you’ll only be printing 10-16 pages depending on your size. Each size has 3 sizes nested above and 3 below to facilitate grading if that is a concern.

Our cup sizes are numbered rather than lettered since I think lettered cup sizing can be a little confusing when you’re not using traditional bra band sizing (we’re not), but our pattern goes from approximately A-DD. It is possible to go up more cup sizes with some creative pattern tracing and I will explain how to do that in an upcoming blog post. Oh and our French translation will be ready in a week or so!

Buy Sophie Pattern


I know sewing swimsuits is intimidating and I wanted to remedy that. For the first time we’re offering an online sewing workshop! In Sewing Your Dream Swimsuit: The Supportive Swimwear Workshop, I walk you through Sophie construction from start to finish on camera. Not only will you learn how to work with swim fabrics & lining, insert swim elastic and sew a foam, underwired cup (on a regular machine or a serger!), but we’ll talk about fitting, pattern modifications and swimsuit construction in way more depth than I could ever reasonably cover in a sewalong. The workshop has 11 lessons and spans almost 4 hours; you can work at your own time and pace. The class teaches a great mix of swimwear and bra-making skills and I’m really happy to be able to offer it. The pattern is included as a free bonus with the class and the entire thing is currently 20% off for the rest of the month! If you’d like to know more, check out the trailer below.

Enroll in workshop!


Finally, it was important to me that we make sewing this pattern as easy as possible, so we’ve put together some really beautiful kits that include swim fabric, lining, cup foam, hardware, elastic, stretch needles, channelling and underwire! I have extremely limited quantities of most of these  (2 kits already sold out in our newsletter pre-sale!) so I’d act quickly if you’d like one for yourself. I won’t be carrying permanent stock so the kit will only be available for a limited time.

*Please note there is no additional discount if you purchase a kit along with enrolling in class; we’re using separate platforms and there was no simple way to do that so we’re just offering the flat 20% off rate on the workshop until the end of June. Thank you for your understanding!

Sophie Swimsuit Fabric kit // Closet Case Files Sophie Swimsuit Fabric kit // Closet Case Files Sophie Swimsuit Fabric kit // Closet Case Files Sophie Swimsuit Fabric kit // Closet Case Files Sophie Swimsuit Fabric kit // Closet Case Files Sophie Swimsuit Fabric kit // Closet Case Files

Shop Sophie Kits

Phew!! So much information, thanks for sticking it out to the end. Even though I’m not hosting a sewalong, I will be sharing lots of Sophie related posts in the month to come. YAY SOPHIE SUMMER!

I hope you like the pattern! I really wanted to offer a more supportive swimwear option for you all and I hope this hits the spot. A big special internet hug to The Sophie herself for being such a great friend and cheerleader these last few months. Her creativity and spirit have inspired me for many years. I’d also like to give major props to my wonderful new model Yasamine; her beautiful smile and energy gave me life in the home stretch.

Let me know what you think and if there’s anything you need more information about in the comments below!

  • Arghhhh congratulations!!!! The props set it off perfectly 😉

    • YOU’RE A GENIUS!!!! Thanks for the great idea. xoxo

  • Well done Heather! This looks like a truly awesome pattern. I’m so excited by all those cup sizes.

    • Thanks Debbie! There should eb one for you in there 😉

  • So impressed by your quality of work! I am just about to have a baby, so not much time for sewing. But I am looking forward to taking that class and making that sexy swimsuit at some point!! Well done!

    • Thank you Andrea! Hopefully the baby will let you have some sewing time 😉

  • Mandy Varelis

    Congratulations on your latest pattern! Sophie is a beautiful swimsuit and I can’t wait to try it! I already made a swimsuit this year, so it might have to wait for next summer, but you bet I’ll be stalking the interwebs for finished projects to swoon over!

    • Well you can never have to many swimsuits 😉 (I have approximately 20 right now! Samples forever!)

  • Such a beautiful and flattering pattern Heather!! Great job. If i wasn’t 8.5 months pregnant I would make it today.

    • Hahahaha I would love to see that though!

      • Not me! Lol, maternity hack coming the next few days by chance ? ; -)

  • verykb

    Great design, the cups and support looks amazing! The kits are a super idea too

  • Oh Heather, once again you release a gorgeous pattern when I’m on a purchasing freeze… BOOOOO… Will have to negotiate this one with hubby for sure, as I really want to do the workshop too. Loving this tho!

    • Just be like “Imagine me wearing this.” He’ll be like “WHATEVER YOU WANT HONEY”.

  • Wow! Love love love! Congratulations on another great pattern 🙂

  • Lisa

    I just begged you to make something along these lines in my second to last blog post. You read my mind! I’m really excited to see this. I think it is much needed and fills a true hole in the sewing scene. I hope it is wildly successful for you, and I think the online class is a great idea.

    • Link please 😉 I actually wanted to get this out last year but I needed more time. So glad to have read your mind!

  • LOVE! Love how much coverage it gives without being too covered 😉

    • I chose a slightly higher underwire for that reason 😉

  • Congratulations Heather!!! I’m blown away by how professionally you’ve put this whole thing together, you’re a unique force in the sewing world the way you’re offering the pattern, kits, the workshop all in a big gorgeous package deal like this. Very very impressive. And that promotional video! just so very professional and you’re absolutely gorgeous, of course! Well done, on the whole fabulous endeavour. Also, it was so nice to hear your voice! I often wonder what our sewing friends sound like in real life, and it’s absolutely brilliant to hear your lovely accent. Now to head off and present my own Sophie swimsuits… 😉

    • Thank you so much Carolyn, that made me feel absolutely wonderful. Love you so much and I’m so grateful for all teh amazing support you’ve given me over the years! Glad you think my accent is lovely; I actually dropped a few canadian “aboots” in there a few time.

  • *starts slow clap* BRAVO to this whole post! the pattern, the workshops, the kits, the VIDEO!!! You’re just out here doing the damn thing… I support it.

  • Looks great. Love the kit and workshop options too. You mentioned telling how to creatively increase cup sizes in a future post, which would be awesome. What would your recommendation be regarding selecting an underwire size? I am well outside your range, but love you swim patterns.

  • I’d like to insert that emoji with hearts for eyes here, please? Because that is how I’m feeling right now. This pattern is amazing, Heather!!

    • Inserted emoji accepted! So happy you like it Birgit!

  • kellicousins

    Damn, girl, this is amazing and it looks fantastic. I’m already imagining it as just a standard bra/panty set because it’s too fabulous not to wear year-round. Congratulations!

    • I am planning a bra hacking post!!!

      • kellicousins

        Hallelujah! (And thanks in advance!)

        • kellicousins

          Also, this is totally unrelated but I wanted to complement you on your grading. I’m looking at the Sallie and I love how your sizing doesn’t just go bigger on the volume of the pant leg around the hem for the larger sizes. It’s very clever of you to think about the volume of the leg in proportion with different body sizes — and it keeps me from having to hack inches off the side seams (which I just had to do with the otherwise-fabulous Inari).

          • I’d love to take all the credit but I work with a really skilled grader who knows what the heck she’s doing 😉

          • kellicousins

            Please let her know I think she’s a gem.

      • Yay that was going to be my question!

      • sallieforrer

        Yes I was thinking this same thing!! Sophie bras and Sophie bustier tops…

  • Sarah

    This is my dream swimsuit AND YOU RELEASED IT ON MY BIRTHDAY!! I have purchased the workshop and am so excited to get started. Thanks Heather Lo – you are amazing!

    • HAPPY BIRTHDAY SARAH!!! So happy that we could time it so perfectly 😉

      The PDF files are located under “Materials & Resources” in the class course list!

      • Sarah

        Yep! I just didn’t scroll far enough. Squee! I can’t wait to make this.

  • Kate English

    Well hot damn!!! This is really fantastic & you have outdone yourself! 55 sizes?!?! Holy s**t! Congrats on the gorgeous release! My body is freshly post-third-baby, and I bought a black skirted tankini for this summer (ugh), but perhaps when my body is more back to normal I will venture into bathing suit-making territory. These are gorgeous and I love the fabric pairings in the kits!

    • I’m not gonna lie. I had a few weeks in front of the computer trying not to cry! Hoping you venture into the territory…. the water is warm!

  • sallieforrer

    You are such a freaking inspiration!! This suit is just BEYOND words. Its so SO good! What an achievement! AND the fabric kits and video class on top of all of it. I kind of want that video class just so it seems like I’ve teleported you into my sewing room to hang out for a few hours! Virtual Heather!!
    Anyway, Please take a vacation now, okay? You’ve earned it. This was a phenomenal launch. You should be SO. PROUD. Sending you internet hugs and kisses xoxoxo

    • We rented a houseboat this weekend and I will be lying on it in Sophies all damn weekend long!

  • WOO HOO! Congrats on Sophie’s release Heather!! {{{Me clapping joyfully!}}} I’m tellin’ ya…these kits are making me swoon…like seriously weak at the knees! And I too, love hearing your voice…it really does add another layer of familiarity, without being weird, LOL.

    Hi Yasamine! It’s lovely to meet you. You are indeed adorable and I can see how your smile would have fueled Heather onward in the home stretch!

    • Thanks Sue! You’ve been amazing throughout this process! xoxo

  • The “penultimate” swimsuit? So…the second to last swimsuit? That’s what penultimate means, & thus, I am confused.

    • Hahahaha I thought it meant ULTIMATE ULTIMATE ULTIMATE. As in, the last swimsuit you’ll ever need? I should go fix that….

      • A common mistake, really. I always remember when “penultimate” means by remembering a time I was teasing a friend who didn’t have much luck with the ladies, & I called him “the ultimate man”. He replied, “More like the penultimate man,” which made me laugh so hard.

  • Frankie

    First off, dang girl! I am going broke because of your fantastic kits! I am a sucker for fabric kits though… Secondly, I scrounged up some under-the-sofa cash (this is what I call my husband’s wallet) to come back and snag the red lace + black kit, and I missed out. Boo!
    Where did you find lycra with lace? Is there a magical portal via mouse clicking that I could buy such a thing? I like the purple modeled version as well. Such an awesome pattern! You rock!

    • HI Frankie! Sorry we sold out of the lace… I bought the last roll from my wholesaler. You might try Spandex House for the print I used with my plum sample – I bought it there last year and they may still have some in stock.

      • Frankie

        Huzzah! I found the fabric! Thanks so much for the info!

        I knew I should have bought that kit on Monday with the others. Kicking myself for it! This is my first time sewing a swimsuit, so I’m excited/nervous!

  • Kathryn

    Welllllllp. Looks like I’ll be attempting a swimsuit, after swearing up and down I would never, ever attempt anything resembling lingerie. I’m going for the two-piece, no less. This two-piece looks like it has enough coverage to keep me confortable, another first. Tell me, do you reckon this pattern would work without the foam in the cups? The molded cups are cute as hell, but I prefer a slightly softer look on myself…

    • YOU CAN DO IT!! And if you don’t have a big bust you can probably skip the underwire. 100% you can make this without foam. I just posed a tester make on my Instagram where the cups weren’t lined with foam….

      • Kathryn

        Oh, no, I cannot go without an underwire, lol. But I WILL skip the foam. Thanks very much! Next question: should I find something in a thin non-stretchy to line the cups with, to replicate the non-stretch quality of the foam?

        • Nope. You can just use swim lining! It’s all covered in the instructions.

      • Kathryn

        And, I havebeen aboiding lingerie sewing because every time we have to deal with lingerie or dance alterations at work, it makes us crazy. But, I think this swimsuit will be a good opportunity to refine my ‘complicated stretch’ skills in a low-pressure setting. ????

  • Sarah

    I’m still a sewing novice, but that video and your enthusiasm make me feel like I could really do the dang thing and make this suit. If I wanted less coverage on the bottom, are those sorts of changes covered in the workshop as well?

    • Hi Sarah! You can totally make the suit! I cover how to make the bottoms lower waisted, but if you wanted a higher cut leg you’d have to do that yourself. I would just trace off the leg from a swimsuit or pair of underwear you already own.

  • Jane

    Likely dumb question, but can you make the suit with the foam cups but without the underwire?

    • Totally! I would sew a little channelling in though, just to conceal the seam and make it neat on the inside. You could just get away with sewing it in and then topstitching it down once form the outside after you grade your cup seams.

  • Amanda Russell

    Really, really excited about this!! I’ve wanted to make a swimsuit for some time now but rarely do swimsuit patterns cater to those of us who need extra support – and this one does that while still managing to look super sexy – BRAVO!! I’m so grateful you did kits too – sourcing all that extra stuff is more than my brain needs ^_^ I will be making a Sophie for Vegas this summer – whoo hoooooo!!!! 😀

  • Amy

    Wow! I love the top of this suit! Definitely a pattern to keep in mind for when I get through some more on my “to sew” list and am ready to try something new. This is the type of bathing suit top that would catch my eye in a store.

  • What a couple of fabulous looking patterns! Love the fabric combinations you picked for the kits too. And you look so glam in the samples. Now if only I know how to swim or live in a country with beautiful hot beaches…

    • That’s not me! I used a wonderful model named Yasamine.

  • Dear lord how did I miss this!? 2 months later. I wish I would’ve seen it before my vacation. Super excited! It also looks like an amazing segway into bra making. *happy dance*