Dive into Swimwear Sewing: Five Essential Tips

Sewing your own swimwear is a lets you customize fit, style, and fabric choices for that perfect beach-ready look which can greatly reduce the stress that can happen with swimsuit shopping! However, swimwear sewing comes with its own set of challenges, primarily due to the stretchy, slippery nature of swim fabrics. Last summer I tried to make my own swimwear for the first time. Overall, it turned out better than expected but I learned a lot from the experience, and I'm here to share these tips with you! 

Here are five essential tips to help you dive into swimwear sewing with confidence and achieve professional results!

1. Use Stretch Needles

When working with knit fabrics, particularly those used for swimwear, using the right needle is crucial. Stretch needles are specifically designed for knit and stretch fabrics. Unlike regular needles, stretch needles have a rounded tip that easily slides between the threads of the fabric, rather than piercing them. This reduces the risk of skipped stitches, which can weaken seams and affect the overall durability of your swimwear. Be sure to use a fresh stretch needle to avoid any snags or damage to your fabric. I tested out a few different needles while sewing my bikini last summer as I wanted to make sure I used the correct one. Be sure to run some tests to get the right size needle for your material!

2. Elastic Insertion

The elastic in swimwear plays a vital role in maintaining the swim suit's shape and fit. Ever walk out of the pool or ocean and have to hold on to your swimsuit?? Most likely that's because the stretch and elastic wasn't the greatest quality or lost it's stretch! Choosing high-quality swimwear elastic is essential because it needs to withstand chlorine, salt water, and sun exposure without losing its elasticity. Regular elastic can degrade quickly in these conditions, leading to a sagging or misshapen suit...and we don't want to deal with that lol When inserting elastic, ensure it's evenly stretched and securely stitched to prevent it from twisting or slipping inside the fabric channels. Zigzag or serge the elastic onto the edges, then fold it over and stitch again for a clean, secure finish. Zigzag stitches are 100% your friend in this instance!

The zig-zag stitch here helps to give the suit stretch while still holding the fabric pieces together!

3. Lining

Lining your swimwear is not just about aesthetics; it significantly enhances comfort and durability. Swim-specific lining fabric is designed to be lightweight, stretchy, and resistant to chlorine and sun damage. It helps provide coverage, prevents the main fabric from becoming see-through when wet, and adds an extra layer of support. Swimwear can already be exposing so no need making it more! When cutting your lining, make sure it matches the stretch and grain of your main fabric to ensure a consistent fit. Sew the lining with the same care and techniques as the outer fabric to maintain the integrity of your swimwear. Most fabric stores that carry swimsuit material will have lining fabrics in white, nude, and black to help match to your fabric.

This swimsuit was actually lined with an older swimsuit lining I reused!

4. Test Fit

Before you commit to cutting your final fabric, make a mock-up of your swimwear in a cheaper, but similarly stretchy fabric. BE SURE IT STRETCHES!! I made a mock-up in a cheap knit material which worked well to make sure my final piece would fit me. This step allows you to test the fit and make any necessary adjustments without risking your expensive swim fabric. Pay close attention to how the mock-up fits around key areas such as the bust, waist, and hips. Make notes of any alterations needed, and apply these changes to your pattern. While sometimes you may just want to jump right into the water of the swimwear...pun intended..it's best to make the mockup to get the correct fit for yourself!

A tie closure for swimwear is also a great shortcut to making sure the suit fits you! 

5. Walking Foot or Knit Foot

Sewing stretchy fabrics can be tricky because they tend to stretch out of shape as they pass through the sewing machine. This was probably my BIGGEST failure with my bikini I made last summer. See how the neckline is puckering and stretching...I used the wrong presser foot and stitch causing it to stretch out. Using a walking foot or knit foot would have helped to manage this issue (so learn from me!!). A walking foot has feed dogs that move the top layer of fabric at the same pace as the bottom layer, preventing stretching and slipping. A knit foot, on the other hand, is designed to glide smoothly over stretch fabrics, reducing the likelihood of puckering or distortion. A knit foot is smaller than a walking foot, so if you don't want to commit to the walking foot a knit foot is a great option! Both tools help you maintain even stitches and prevent fabric from stretching out of shape during sewing.

See the waviness around the bikini top...don't be like me! Use a walking foot or knit foot with the proper stitch tensions!

Bonus Tips

• Use a Serger: If you have access to a serger, use it for seams that require extra stretch and durability. Sergers create professional, stretchy seams that are perfect for swimwear but you can sew swimwear on your home sewing machine!
• Choose the Right Thread: Use polyester or nylon thread for swimwear, as these materials are resistant to the harsh conditions swimwear is exposed to.
• Practice Patience: Swimwear sewing can be a test of patience, especially if you're new to working with stretch fabrics. Take your time, and don’t rush through the process.

By following these tips, you'll be well on your way to creating swimwear that not only fits perfectly but also stands up to the water! Be sure to check out my Amazon Storefront where I have linked different tools to help in your swimwear sewing journey! Happy sewing!

Want to watch the video where I made my swimsuit? Check it out below!