Bralette to Swim Top: Converting the M4M Bridgette

A couple years ago I decided to make a swimsuit. That first attempt produced a wearable result, but it was significantly flawed. Instead of throwing in the towel–or the slippery nylon/spandex swim knit–I took it as a challenge. The next swim project was more successful, and I have then been addicted to sewing swimwear. I have tried a variety of swim patterns and am always on the lookout for new ones, but I also look at non-swim patterns wondering how they would work at the beach. When I first saw the Made for Mermaids Bridgette Bralette, I knew that I must make it a swim top, but I also knew that I would have to overcome some obstacles to do so.


Pattern Modifications

For the record, the Bridgette Bralette functions fine just the way it is. You can see numerous examples on the Made for Mermaids website and their Facebook group of beautiful bralettes made according to pattern instructions using specified materials. But I don’t need a cute or sexy bralette. I need a swim top, and that calls for some modifications.

The first thing I changed was the pattern pieces. I used the racerback option. The pattern is made to use double galloon lace and this back option is made up of four small back pieces, which are then attached to two strap pieces on each side. To reduce that, I joined the upper and lower pattern pieces (overlapping to accommodate for the seam allowance), trimmed the straight edge of the new piece to remove the center seam allowance, and widened the strap piece to match the width of the place where it would meet the racerback piece and attached it to form one cut on fold back and strap pattern piece. As a result, I think the pattern became at least 67% simpler.

The only other pattern piece I modify is the band. Since swim fabric has more stretch than most stretch lace, the band piece is too long for our purposes. I don’t have a scientific way of figuring out how long to make the band. Basically, I put the elastic I plan on using in the band around my underbust and measure where it is snug but comfortable. I cut the elastic at that point, measure it, and make the band piece that length plus a small seam allowance. The height of the band will vary on what size of elastic you use, and that depends on what the top needs to support. Since my RTW bra size is 38DD, I usually prefer 1.25″-1.5″ elastic in bands. If you are smaller or larger, I recommend adjusting elastic accordingly. The band should be double the elastic width plus seam allowance.

Next up for modification is the materials used to create the item. Instead of fancy lace and picot elastic, to make a swim top, you need swim knit (usually a nylon/spandex blend), swim lining (unless you want to line it with another layer of swim knit), elastic (I use .25″ cotton swimwear elastic for much of the construction and wider elastic [1″-1.5″] to add support to the band), and powermesh (optional, but useful for extra support).

Pieces Needed

  • Front cup: cut 2 as mirror images of main, lining, and powermesh
  • Side cup: cut 2 as mirror images of main, lining, and powermesh
  • Back (including straps): cut 1 on fold of main and lining
  • Back upper band: cut 1 of main and lining
  • Band: cut 1 according to personal measures (see above)

cropped pieces

Constructing the Top

Step 1: If using powermesh, baste each piece to lining pieces.


Step 2: Pin and sew the middle seam for each cup so you have a left and right cup made from lining pieces and a left and right cup made from main fabric pieces. [DO NOT follow the pattern instructions for assembling main and lining cups in one step.] Topstitch each piece to reduce the bulk of the seams.

Step 3: Place the lining and main fabric of the left and right cups right sides together (RST) and sew around the side edges leaving the bottom and the straight edge along the outside open using a stretch stitch or serger.


Step 4: Attach swim elastic to sides using a wide zig-zag stitch. Unless noted, I just use a one-to-one ratio when attaching elastic. Leave a 3/8″ space without elastic at the end of the outside edge to reduce bulk in the seam allowance when attaching the front pieces to the back pieces. Turn pieces right side out and set them aside.


Step 5: Pin the lining and main fabric of the back/strap piece RST. Sew with a serger or stretch stitch. Attach swim elastic to the sides and along the neckline (I stretch the elastic slightly through the curve of the neck at the top of the back piece, but it still works okay at a one-to-one ratio). Turn piece right side out and topstitch along edges where you attached elastic.

Step 6: Find the center point of the bottom of the back piece and the top edge of the back upper band lining and main. Cut a piece of swim elastic using the cut chart in the pattern instructions (you knew the actual instructions would come into play at least once, right?). Sandwich the lining piece of the back upper band, the back piece, and the main fabric of the back upper band RST and lining up at the center point of each piece. Pin along the edge, ensuring that the ends of the back piece are secured within the upper band pieces. Sew pieces together using a stretch stitch or serger. Match the center of the elastic to the center of the upper band/back piece and pin. Pin to each end of the seam and attach with a zig-zag stitch, stretching elastic to match the fabric.


Step 7: Lay out the back and cup pieces and match the right cup to the right side of the back and the left cup to the left side of the back. Line up the seams and pin the cups to the back RST joining main fabric to main fabric and lining fabric. Sew with a stretch stitch or serger. [I thought I took a picture of this step, but must not have. I hope the description makes it clear enough.]

Step 8: Start at the center of one cup and topstitch up the cup, down the cup, around the back, and up and down the other cup.

Step 9: Determine how much you want the front to overlap (there is some guidance on this in the pattern) and pin the cups together at that point. Baste or serge around the bottom edges to make it easier to join it to the band.

Step 10: Butt the ends of the underbust elastic together and stitch with a wide, short zig-zag. Sew the short ends of the band RST and then fold it in half with right sides out. Place the elastic within the band and baste the edges shut.

Step 11: Mark quarters of the band and match them RST to the side seams, center front, and center back of the swim top. Sew with a stretch stitch or serger.

Step 12: Try the top on and determine strap length. Safety pin straps in place and trim straps if necessary.

Step 13: Sew straps to the top of the cups by going over the topstitching (matching the stitch line as close as possible). I encourage hand stitching the straps to the liner for additional security.


Step 14: Make or find some coordinating swim bottoms and go rock your new swim top! If you want some bootylicious bottoms, you might want to get the Bridgette and Victoria bundle.

Fabric Notes

Main swim fabric is Aurora Sky and solid black from Zenith and Quasar. I highly recommend their swim fabric for both great quality and amazingly beautiful designs (and good prices and quick shipping…).

Lining and powermesh are from my stash of swim supplies, so I have no idea exactly where they are from but likely candidates are The Purple Seamstress or The Fabric Fairy.



4 thoughts on “Bralette to Swim Top: Converting the M4M Bridgette

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