Tutorial: How to sew a Reversible Swim Tank

Reversible Swim tank tutorial

We spend a lot of summer days in and out of water. Into the sprinkler for 20 minutes, back out, into the pool for 30 minutes, onto something else. And if you think anybody is putting on a wet swimsuit- forget about it!

This means it helps for me to have a stash of swimsuit options available. I’m going to show you how sew up a fully reversible swim tank with completely enclosed seams. I made this for my daughter but the same concept works for a boy tank.

First you need a basic bodice pattern. I’m using our free Cecilia tee.  You want to choose a knit pattern. If your original pattern has sleeves, like mine, evaluate the armhole. Will it be too deep without a sleeve? Your pattern should also be relatively fitted since you’re using this for a swim top. Some people like to size down, I don’t but I’m using this for primarily a “splash around” top. She isn’t doing laps.

For the sake of this tutorial I’m going to refer to my sides as “printed” and “solid”. Either side can be used as the primary or lining side.

1. Cut 1 front and back out of the printed material. Cut 1 front and back out of the solid material.

reversible swim tank tutorial, Once Upon a Sewing Machine

2. Sew the shoulders and sides seams of your solid front and back right sides together using the seam allowance from your original pattern. Repeat with the printed front and back.

reversible swim tank tutorial, Once Upon a Sewing Machine

3. Turn the solid tank right sides out. Keep the printed top wrong side out. Slip your solid top inside of your printed top. They will now be right sides together.

reversible swim tank tutorial, Once Upon a Sewing Machine

4. Pin the two neck openings together matching side seams. Sew. I used a 3/8″ seam allowance. Since I serged my seams I pushed one shoulder seams forward and one backward. If you have used a standard sewing machine finger press open the seams.

reversible swim tank tutorial, Once Upon a Sewing Machine

5. Flip your top right sides out. You’ll now have a finished joined neck and finished side seams. Now we’re going to close the armholes and hem. Fold under the raw edge of the solid and printed armhole 3/8″, pin to secure all the way around and top stitch. I used a zig zag, you are working on a knit so you’ll want a stretch stitch that looks nice on both sides.

swim tank 5 swim tank 6

6. Repeat this same process for the second armhole and hem. You know have a fully reversible swim tank with no exposed seams!

Alternatively you could use a knit bias binding to close your armholes and hem.

Tutorial: Reversible Swim tank tutorial Tutorial: Reversible Swim tank tutorial

Enjoy the sun!

Happy Sewing,


Pattern: Free Cecilia Tee OUSM Designs

Fabric: (Stash) Printed fabric originally Girl Charlee, Red Swimsuit- Fabric Warehouse.

{ 4 comments… add one }
  • Amy Mayen May 31, 2015, 10:25 pm

    Reversible is so cute- who needs boring lining when you can have a 2 in 1? Great idea!

  • Irene June 1, 2015, 1:47 pm

    That is so cool! Love it 🙂

  • Pam @Threading My Way June 2, 2015, 8:53 am

    Great idea and super cute. Way too cold to even be thinking about anything swimming related Down Under. Pinning for next Summer.

  • Ajaire June 7, 2015, 2:59 pm

    We need a bunch of these too. Great idea for a quick swim top!

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