It’s here, it’s here! I’ve waited 9 long months for this weekend – #MDW. Being from Florida, I live for the heat and *slight* humidity. Just a touch, but not enough to make my hair frizzy. Priorities people. The time between Memorial Day and Labor Day is my favorite – late sunsets, running in the heat, grilling… and bikinis! Or one-pieces if that’s your jam. Have you been sewing bras and undies (hopefully Madalynne bras and undies) and are now wondering if and how you can use your lingerie patterns to make swimwear? You’re in luck then beach babes! Below, I’m going to give you a brief rundown on the basics of DIY swimwear as well as the alterations that I made to transform newest DIY bikini kit in the web shop using the Madalynne X Simplicity 8437 pattern for the bikini top and Noelle underwear pattern for the bikini bottom.

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SWIMWEAR 101

FABRIC: For swimwear – bikini or one piece – the fabric must stretch. The most common fabrics have Lycra® or Spandex. It is my top, really it is my only, pick for swimwear. Lycra holds its color and is resistant to chlorine and the sun. Whether it fabric, lining or trims – this is what you want to keep in mind – is it resistant to all those three things? Now, if you’re not the type to go in the water, you could get away with it being not chlorine resistant. If you choose a Lycra® or a Spandex fabric, it will either be a 2-way or 4-way stretch. With a 2-way stretch fabric, the stretch is only going in one direction. You’ll be able to get away with this in a bikini, but maybe not a one piece. Stay away from anything that has natural fibers – cotton will absorb and hold water, and some become see through when wet too.

LINING: You can, and I have used, stretch mesh as a lining. If you don’t have access to swimsuit lining, I think this is an excellent alternative. There is special lining for swimwear though. When shopping online or in stores, look for “swimsuit lining”, which is called helenka some places.

ELASTICS: The key to swimwear elastic, just like fabric and lining, is that it will hold up for sun, salt and chlorine. Normal lingerie elastic won’t. There is a cotton swimwear elastic that is latex free (pictured in image above on the left). It looks very similar to knitted or braided elastic. There is also rubber elastic (pictured on right above). The DIY bikini kit comes with both types of elastic. Most RTW swimsuits that I’ve bought have rubber elastic. I like the quality better, but it is extremely hard to sew. I have gotten in many fights with my sewing machine, even when I’m using a special presser foot that’s supposed to make it easier. The latex free elastic is a breeze to sew. If you’re used to sewing lingerie elastic, it will be a cinch.

PATTERNS: If you’re using a lingerie pattern to make swimwear, you want to compare the amount of stretch the pattern was drafted for. If it’s different by more than 10%, I suggest sizing up or down accordingly.

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USING MADALYNNE’S DIY BIKINI KIT

The newest DIY bikini kit in the web shop uses the Madalynne X Simplicity 8437 pattern for the bikini top and Noelle underwear pattern for the bikini bottom. If you purchased a kit – refer to the below for the changes that I made to the bikini I’ll be wearing all.summer.long.

PATTERN ALTERATIONS

RUFFLE: The finished height of the ruffle is 1” on the top and tapers to nothing at the center front and back. Also, the ruffle is gathered at a ratio of 1:1.25”. So, I cut a strip of fabric that was 1 ¼” high (to account for seam allowance) and tapered to 1/4″ at the beginning and end.

G-HOOK: I reduced the height of the back band at center back to accommodate a G-hook.

FOAM CUPS: Lining adds a little modesty, but you could still have “nipple show through”, especially if the swimsuit gets wet. Each DIY bikini kit includes polylaminate foam and I used it to line the front cups of the
Madalynne X Simplicity 8437. I removed the seam allowances (¼”) on all edges. You can assemble the main fabric, the lining and the polylaminate foam cups separately and then sandwich it between the fabric and the lining, but I found a better/easier way. After I’ve cut out the foam cups, I used a permanent fabric spray adhesive to adhere them all together. I then treated as one layer during construction/sewing. There’s less shifting, and this makes it easier to apply the channeling in later steps.

SEWING

ELASTIC: The way you sew swimwear elastic is different than the way you sew lingerie elastic. For this swimwear elastic, I first encased the elastic in an overlock. See image on left below. Then, I turned it back and sew a zigzag stitch to secure it down. See image on right below.

Also, when sewing the elastic to the bikini top – I shirred/gathered the ruffle and then pin/sewed it before.

G-HOOK: Wrap it around the center bar then sew with a straight stitch as close to the metal as possible. The hook should be facing up, otherwise it will easily fall off. For the side that doesn’t have the G-hook, you will turn it back approximately 1/2″ and sew a straight stitch up and down. This will create a “tunnel” that you can slide into the G-hook.

STRAPS: The pattern does not call for straps, but if you want straps, check out this tutorial by Melly Sews.