Swimwear Sewing Basics

We might have gotten a bit ahead of ourselves here at the CSC during our Swimwear Month. We were so excited to share all the swimwear we’ve been making (check out all the beauties here) that we neglected to share some of the basics of swimwear sewing.  Chicken before the egg, cart before the horse…

Since there are so many excellent resources on swimwear sewing out there, rather than recreate the wheel, we are rounding up some of our favorite tips, tricks and tutorials here today. We hope we’ve covered everything, but please let us know in the comments if you have any other questions on swimsuit sewing that we can help out with!

Swimwear Basics

Seamwork Magazine has a great article on sewing swimwear that covers everything from fabric and stitch choice to adding bust support with cups and underwire. Patterns for Pirates also has a similar article with lots of excellent advice. Kollabora has a whole skillset series for sewing swimwear.

There are also several swimwear sewalongs and tutorial that, although geared towards a specific pattern, are chock full of useful tips applicable to any swimsuit. Have a look at the following:

Bombshell Sewalong on Closet Case Files

Nautilus Swimsuit Sewalong on Seamstress Erin

Lisette Swimsuit Sewalong in the Oliver + S Forum

Jalie 3350 Photo Tutorial/Sewalong

Sew News Soma Swimsuit Sewalong

Mimi G Style Simplicity 1116 Video tutorial

Angela Kane Sewing Swimwear Video Tutorial

Helen’s Closet Reno Bikini Top Sewalong

Swimalong at Three Dresses Project

 

Fabric

Tanya covered swimwear fabric, lining and notions earlier in the month (key words: lycra! spandex!), but here are some additional resources for choosing the best fabric for your swimsuit:

Liesl of Lisette/Liesl + Co/Oliver + S has a written a nice article on choosing your swimsuit fabrics, linings and elastics. Craftsy also has a blog post on choosing the best swimsuit fabric. Seamstress Erin’s fabric choice post is extremely detailed and helpful, with lots of photos. If you want to see the fabric in action, also check out her video:

Cutting

Swimwear fabrics can be a bit slippery and cutting can be a bit fiddly, but there are lots of tips out there that make cutting your swimsuit fabrics quite straightforward. Cut out your pattern with the fabric flat rather than folded to avoid slippage and right side up to help ensure you don’t have any unwelcome print placement mishaps (beware the flower boob!). Make sure the greatest amount of stretch in the fabric is going around your body; typically the greatest stretch runs perpendicular to the selvage. Use sharp cutting tools; many swear by a rotary cutter with a fresh blade, but sharp scissors work fine, too. Pattern weights are ideal, but, if pinning, use sharp pins and try to pin inside the seam allowances to avoid snagging the swimsuit fabric.

Needle

There seems to be a bit of disagreement in the sewing world regarding needle choice for sewing lycra and swimsuit fabrics. Some swear by stretch needles, while others recommend ballpoint. I’ve personally found stretch needles to work best for me. Threads magazine suggests stretch needles for highly elastic fabrics like spandex and lycra. Schmetz itself also suggests stretch needles for highly elastic knits. The difference between the ballpoint (sometimes labeled “jersey”) needle and the stretch needle is the deeper scarf and special eye for preventing skipped stitches. Check out this Schmetz needle guide for more info.

Thread

Many sewists recommend using polyester all-purpose thread rather than cotton as it better withstands exposure to chlorine and salt. Some people also recommend using wooly nylon thread in the loopers of your serger for a super strong stretch.

The McCall’s Cosplay blog has an insanely helpful post on sewing stretchy fabrics, including thread choice and stitch type. I love the troubleshooting of some common spandex sewing pitfalls.

Stitch Type/Length

You might think that having a serger is a necessity for sewing swimwear, but really a basic zig-zag stitch is your best friend when sewing a swimsuit. Depending on what part of the suit you’re sewing (elastic vs seams), you will need to vary your zig-zag width and length. Experiment a bit on scraps to find the best stitch for you and your fabric.

You can also use a serger for many, but not all, steps in sewing a swimsuit, so if you have one, that’s great. Finally, for major seams, if you have the “lightning bolt” and triple stretch stitches on your machine, which are a sturdy choice.

Craftsy has some incredibly helpful spandex sewing tips and Peek-a-boo Patterns’ tips on stitch length for swimsuit fabric are worth a look.

Swimwear Elastic

Whether you’ve chosen rubber or cotton swimwear elastic, applying the elastic to your swimsuit can be the most challenging part. Almost all swimsuits will have elastic applied to the legholes, but many also have elastic on the cups, back and waist, too, so nailing your elastic application is really key to sewing a successful swimsuit. Check out these tips below on sewing elastic:

Indiesew has an informative post with lots of photos on sewing swimwear elastic.

Jalie has a helpful photo tutorial as well as a video on sewing elastic using their method:

Seamstress Erin also has a great post and video covering the all-important elastic insertion:

Strapping

Many swimsuits have lots of strapping, much of it supported with elastic. There are different methods for making these straps. Beverly Johnson demonstrates her preferred  elastic strap method as part of her yellow polka dot bikini sewalong. Emerald Erin has an enlightening tutorial for two different ways of sewing elasticated swimsuit strapping (my personal favorite method is Erin’s Method 2).  

Fleur of Maison Fleur has a helpful video tutorial on sewing rouleau straps with elastic:

Bust Support

Seamstress Erin was kind enough to give us the rundown on inserting swim cups and boning into our swimsuits earlier in the month, but sometimes the ladies need even more support. Check out these other options for ensuring your swimsuit is supportive: Seamwork’s article covers swim cups and underwire, the CSC’s own Jenny of Cashmerette walks you through adding a swim bra into your swimsuit, and Beverly Johnson has a whole Craftsy class on sewing a supportive swimsuit, including using pre-formed cups or a full bra. The Three Dresses Project has a post from Norma Loehr at Orange Lingerie on adding bust support to your swimsuit.