DIY V-Neck One Piece Swimsuit:
The Sarah One Piece

The Sarah one piece is a great basic. It sits high on the hips and features a dramatic but flattering v neckline. It fits snugly along the waist, making it perfect for anyone trying to emphasis an hourglass shape.


  • Pattern (or draft your own)
  • Swimwear/rubber elastic
  • Swimwear fabric (see where I buy my fabric here)
  • Lining (or use regular swimwear fabric to make it reversible)
  • Pins (optional but recommended)
  • Scissors/cutting mat & rotary cutter
  • Acrylic ruler (optional)
  • French curves or fashion ruler (if you plan to make adjustments to the pattern)

If you prefer video directions, you can watch below. Otherwise, keep reading!

Step 1

Cut your pattern out and tape it together. If you’re using my pattern, it should look something like the photo to pictured once assembled.

Since torso sizes vary widely, it is recommended you use the lengthening/shortening line marked on the pattern. I am 5’8”, and I lengthen the pattern by about 1-2”.

Step 2

Cut each pattern piece according to these specifications:

**Seam allowance is NOT included, adding 0.25” allowance is recommended

Piece 1 (Left bust): Cut 1 fabric, 1 lining

Piece 2 (Right bust): Cut 1 fabric, 1 lining

Piece 3 (Front bottom): Cut 1 fabric, 1 lining

Piece 4 (Back): Cut 1 fabric, 1 lining

Straps (Not included in pattern): Cut 2 fabric, 2 lining. Make them 2.25” x 5-9”, depending on your preference and torso length. I made mine 7”, but I should’ve done closer to 6”. If you bought the pattern, there’s a strap length guide. I always recommend making your straps longer than needed, since you can always go back and trim.

For the rest of the tutorial, the lining will be called the “lining”, and the swimwear fabric “self”.

Step 3

Get your straps. You should have four strips cut, 2 in self, 2 in lining. We’re going to start by sewing the straps together. To do this, match them right sides together (lining with self) and sew along the long edges. Then go back and attach elastic right on top of where we just sewed.

Once they’re sewn, take them to the right side.

Step 4

Next, get your bust pieces (pieces 1 & 2). Match the lining with the self, right sides together. Sew along the inner bust and the outer shoulder edges. Then go back and add elastic.

Step 5

Now take your straps, and insert them inside the strap opening of the bust pieces. Make sure right sides are together. Pin down.

We will sew across this opening, sewing all four layers in one step.

Once this is done, take the piece back to the right side. Sewing four layers at once leaves a nice clean finish, which ultimately helps the elastic lay flat and prevents the fabric from sliding while being worn.

For the rest of this tutorial, we will be using this method.

Step 6

Now get your front bottom pieces (piece 3). Match the lining and self, right sides together, then sew just along the leg holes. Attach elastic as well.

Step 7

We will next attach the cups to the front bottom, so that we have one complete front piece. To do this, insert your cups inside the front bottom, right sides together. You’ll want to pin on each edge of the cup, but don’t worry about pinning all along where you’ll sew, since you’ll need to stretch as you go to fit.

If you’re doing this correctly, your cups should be in between the two layers of the front bottom.

Sew across this line, and stretch the front bottom as you go in order to fit the length of the cup and to be able to sew in a straight line.

Again, make sure you’re sewing across four layers of fabric.

It might be easier to sew in one cup at a time, to ensure you’re fitting it correctly.

After you’ve sewn across, take the suit back to the right side through one of the open edges. Once again, we have a nice, clean finish that secures the lining to the self from the inside.

Step 8

Take your back pieces (piece 4) and match lining and self, right sides together. Just like last time, sew just along the leg holes, then go back and attach elastic.

Step 9

Next we want to attach the front piece to the back piece by sewing the gusset area. To do this, insert the front piece inside of the back piece, making sure right sides are together. Pin the two gussets together, then sew straight across, across all four layers of fabric.

Take the suit back to the right side.

Step 10

This is where sewing across four layers can get tricky. Take this step slowly!

Lay your suit down as you would normally. You want to grab the bottom layer of fabric, which will be the self of the back piece. Take this layer of fabric and wrap it around to the front, matching right sides together and thus encasing the suit.

We now will sew the sides. Match up the four layers of fabric, and pin only at the top and the bottom of each of the sides.

We want to sew across these four layers of fabric, on both sides of the suit.  

We’ll be stretching to fit as we sew again, so pins aren’t necessary except at the top and bottom edge. If you need to use them to make sure you’re sewing across all four layers, then try to pin while the fabric is stretched.

Sew the sides, taking your time to ensure all four layers are being sewn.

Step 11

You can now see that the only open seam is the top of the back, where our straps will be going.

While still inside out, pin down your straps where you want them to go, making sure they aren’t twisted and that right sides are together.

We’ll sew all across this open seam, sewing the straps as we go. For most of the seam, you’ll only be sewing across two layers of fabric, except where the straps are of course.

In between the straps, leave a 2” hole.

Step 12

Once this is done, find our 2” hole and take the suit completely back to the right side. The final step is sewing this hole, which you can either do with an invisible stitch or a top stitch. If you want to insert a clothing tag, it’s a good time to do that.

That completes this tutorial! This suit is one of my new favorites, and I had a lot of fun experimenting with this new method. I messed up so many times, but something clicked and I’m glad I finally figured it out.

The way this is sewn is different than the sandwich method primarily because the lining and the self are secured to each other from the inside. This prevents the suit from sliding when it’s being worn, and it also makes the elastic lay flat.

Overall, it’s slightly more challenging than the sandwich method but it totally pays off.

Make this suit in a luxury fabric, and you could easily sell it for $100-$200.

Thanks for choosing Edgewater Avenue & myself for your sewing tutorials, and I hope you visit the shop to see some more goodies- patterns, fabric, and even more stuff soon.

Happy sewing!