Cottesloe Swimsuit Sewing Tips

Mac of Sew Altered Style sewed up the Megan Nielsen Cottesloe Swimsuit pattern and is walking us through how she got a great fit on a summer wardrobe basic!

When I was asked to sew up a version of the new Megan Nielsen Patterns Cottesloe Swimsuit, my immediate answer was OBVIOUSLY!  While swimsuit sewing isn’t my absolute favorite (a sentiment both Katie and I share), there is something SOO nice about having a swimsuit custom made to fit your body and dimensions.  My pushing 40, post-two pregnancies, body requires quite a bit of adjustments to get a suit that fits – and this sewing pattern has JUST what I needed – without a bunch of extra.  A solid summer workhorse – and you all know how much we enjoy a wardrobe workhorse around these parts! Read below for more about my experience, some tips for sewing swimwear, and the adjustments I made to make this swimsuit fit me better than anything I could have bought in a store.

      The last time I sewed a swimsuit – it was a one piece.  Let me start by saying – it is one thing to sew up a one-piece and show the entire World Wide Web your figure – but it takes a whole new level of confidence to sew and share a two-piece.  There‘s definitely skin showing in places that feel intimate – and vulnerable. But at the same time – this is the body that I have. This is my season of life, and it deserves to be celebrated and clothed in garments that make me feel good about myself – and this swimsuit does the trick.

            Pattern Spotlight

            Megan Nielsen Cottesloe Swimsuit

            Pattern Description

            According to the Megan Nielsen site:

            Cottesloe is a classic one piece swimsuit and mix and match bikini sets. Pattern features athletic elements, four variations and includes detailed instructions to guide you through swimsuit construction techniques. View A is a one piece swimsuit with low scoop back, shelf bra and ties at the back. View B is a one piece swimsuit with high scoop back. View C is a bikini top and a low rise bikini bottom. View D is an athletic inspired bikini top and high waisted bikini bottom with wide waistband. All versions are able to be fully lined.

            For reference, I sewed up view D, and chose to line them both.

                Pattern Alterations or Design Changes

                Based on the size chart below – I am technically between and 6 & 8 bust  (35.5”) and hips (37.5”) and a 12ish waist.  As a reminder I am 5’2.5” (159 cm),  and have a short torso with longer legs.  I typically remove 2 inches from the bodice of patterns (0.5” above the bust and 1.5” at the waist), but since this isn’t a one-piece, I just removed the 0.5” above the bust (in other words, I shortened the straps). 

                  Pattern Alterations or Design Changes

                  In order to get the best fit, I made several changes to the bikini top and bottoms – I walked through those changes below:

                  Bikini Top:

                  • Cut a straight size 8 – no blending
                  • Shortened Straps – (forgot to reduce the arm elastic 1″ – whoops – I thought that went on too easy!)
                  • Added Push-Up Cups – you can find the link here
                  • *Lengthened underbust elastic – I added 2″ to the measurement.  This band was so tight that it was EXACERBATING my love handles.  No thanks!

                  Bikini Bottom:

                  • Cut size 8 blended to a 12 waist
                  • *Lengthened the waist elastic considerably (added 3″ – real talk, I was probably slighted bloated – this figure is never quite accurate) 
                  • No change to leg elastic (cut size 8)

                  *Note, I used regular elastic from Joann’s.  Not sure if this measurement was also impacted by not using “swim elastic”


                    Three tips for Sewing Swimsuits:

                    I won’t go into the nitty-gritty on swimsuit sewing since, honestly, so many people have covered this topic in pretty major ways.  I have the Closet Case Sophie Swimsuit teed up soon so I have the video through her class, I also own a (formerly Craftsy) Bluprint class on sewing swimsuits.  Either of those or other blogger’s posts can help you walk through construction.

                    So, without further ado – my top three sewing tips for sewing a swimsuit:

                    1. Use a serger if you have one – though it isn’t necessary you could in fact do this with a sewing machine only as the fabric will not unravel like a woven does.  The serger allowed me to speed up my workflow – which was much appreciated.
                    2. Fit/tweak as you go – I was REALLY skeptical about the waist and bra bands so I basted them in and tested the elastic by wrapping them around my body.  Turns out, I had HORRIBLE rolls with the fabric bands cut according to the size I selected (8 bust, 12 waist, 8 hips).  If you tend to be “soft” like me then you may find that you need a looser waistband.  Lengthening the elastic significantly reduced the visible rolls (let’s be honest it won’t remove them all.
                    3. Catch the raw edge of the arm, leg and neckline seams in the topstitching.  When I stitched in the middle of the elastic or wasn’t consistent about this step – I found that my “facing” would flip out.  This made my suit look pretty homemade.  Now, I went back on and top stitched using the zigzag stitch on the wrong side of the fabric.  This helped me make sure I was indeed catching that edge.  Yes, this means in some places my seams have two rows of fabric, but I left them in because they are barely noticeable.


                      For this swimsuit, I used this fabric from Joann’s from a couple years ago.  Believe it or not – this was a one-yard remnant that I purchased there (which means it was 50% of the post sale price – crazy, I know) on a whim.  The last swimsuit I made used this same material.  It was relatively easy to sew with, and didn’t curl too bad.  Honestly, the ONLY challenge I know that happens with this fabric is that the underside is light colored, so when this fabric is stretched to its limits (which can happen on bands in particular), the fabric ends up looking slightly distorted.  I didn’t have that problem with this pattern because I made my bands looser than intended. 

                      Final Thoughts

                      Overall – if you are new to swimsuit sewing – give this pattern a try!  If you aren’t – this pattern can serve as a great first foray into it.  If you are more experienced, you can easily hack and adapt it for all kinds of uses (including underclothes and athletic gear)!  Let us know in the comments below what you think of the new pattern! And in case you want to continue to support our work, please head to our Facebook Page and give us a like and a follow!

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