Hey everyone, Holly here again with another Cottesloe hack. I am SO excited about today’s tutorial. It’s a 2-in-1, well actually 4-in-1! With just one technique, you can add a skirt or a peplum one piece! Or a skirt bottom! Or a one-piece with a little peplum ruffle detail at the waist! So many options. And the best part – it works with both the adult and mini sizes.
I wanted to keep this as simple as possible. So instead of trying to calculate a circle peplum/skirt, I’ll be showing you an easy way to do it with the slash and spread method. Super simple! And even though it is all the same method for every option I mentioned, I will show you one of each – one done on a one-piece and one done on bottoms.
Are you ready for this one? Let’s get started!
Skirted (or peplum) one-piece
I’ll show you this one on mini Cottesloe, but it can be done just the same in the women’s size!
Decide where on the swimsuit you want your seam to be. I decided to do mine right at the ‘lengthen or shorten” line. Make sure you mark at the same point on both the front and back.
Cut both the front and back in half at these lines.
Place blank paper underneath your new 4 pattern pieces and tape it down. Add 1/4″ seam allowance to both the top and bottom sections of both your front and back pieces.
Re-cut your new 4 pattern pieces with the added seam allowances.
Now to make the skirt/peplum:
Measure the front pattern along the new seam line, and then again along the back seam line.
Front seam line measurement + back seam line measurement – 1/2″ = Peplum length.
Now draw a rectangle on a piece of paper where the length is the ‘Peplum Length’ measurement that you calculated above. The height depends on how long you want your skirt or peplum to be + 1/4″ (add another 1/4″ to the height if you plan on hemming your peplum/skirt. I chose not to)
Cut out your rectangle and divide it into 10 equal sections.
Now cut along each line, from bottom to top. Cut right up to, but not through, the top of each line. So it will still be connected and have “hinges”.
Place a large piece of paper underneath. Starting at one side, tape down the first section. Spread each section between 1 1/2″ -2 1/2″, taping as you go.
The more you spread, the fuller your peplum or skirt will be. So the more you spread, the better. I went with 2 1/4″. When all is done, you want to at least have a 180-degree half circle (you’ll see this below). No less. The closer to a full circle, the better.
Once you spread and tape every section, you will want to add on to each end as well for added fullness. For example – I spread each section 2 1/4″, so I added 1 1/8″ to each end.
Cut out your new spread peplum pattern piece.
As you can see, this one ended up being just over a 180-degree half circle. You don’t want any less than this, or you won’t have any fullness!
Cut one peplum piece out of your fabric, along with your front and back pieces.
Sew the front and back of the top section together at the side seams and shoulder seams.
Sew the bottom section together at the side seam and crotch.
(if you need help with construction, gusset, or full lining, see the links below for the sewalong posts!)
Fold your skirt/peplum in half and sew together at the side seam 1/4″ from the raw edge.
You can also hem your peplum or skirt now if you would like, by turning under 1/4″ and topstitching with a twin needle or zig-zag stitch. I chose not to hem mine because there isn’t a concern about swim knits fraying!
Turn both of the peplum/skirt and the bottom section right side out.
Slide the peplum/skirt over the top of the bottom section so that the waist edges line up. Pin in place along the waistline.
note: you can line up the peplum side seam with either of the bottom side seams or along the centre back.
Keep your skirt and bottoms right side out, but turn the top section inside out.
Slide the skirt/bottoms section inside the top section until the waist seam edges are lined up.
The right sides of the fabric will be facing each other.
Re-pin all three layers together.
Sew the 3 layers together 1/4″ from the raw edge.
Flip your top section up so the whole suit is right side out – and voila! You have a skirt or peplum in your waist seam!
You can now sew in all of your elastic along the neckline, armholes, and leg holes to finish your suit.
Here’s what it looks like on my little lady from the back…
… and the front!
Peplum (or skirted) bottoms
This is the same concept as above, so I’m not going to show you every single detailed step. See above if you need help!
Measure along the waistline of both the front and back pattern pieces.
Front waistline measurement + back waistline measurement – 1/2″ = Peplum length.
Cut out a rectangle where the length is the ‘Peplum Length’ measurement that you calculated above. The height depends on how long you want your skirt or peplum to be + 1/4″ from seam allowance (add another 1/4″ to the height if you plan on hemming your peplum/skirt. I chose not to).
Divide it into 9 or 10 equal sections.
Now cut along each line, from bottom to top. Cut right up to, but not through, the top of each line. So it will still be connected and have “hinges”.
Place a large piece of paper underneath. Starting at one side, tape down the first section. Spread each section between 1 1/2″ -2 1/2″, taping as you go. The more you spread, the fuller your peplum or skirt will be. So the more you spread, the better. I went with 2 1/2″.
Once you spread and tape every section, you will want to add on to each end as well for added fullness. For example – I spread each section 2 1/2″, so I added 1 1/4″ to each end.
When all is done, you want to at least have a 180-degree half-circle, no less. The closer to a full circle, the better.
Cut out your new pattern piece.
Cut out just one from your fabric.
Sew the front and back pieces of your bottom together at the side seams and crotch seam. (All the pins you see here is because I am fully lining my bottoms).
Fold your peplum in half and sew together at the seam 1/4″ from the raw edge.
You can also hem your peplum or skirt now if you would like, by turning under 1/4″ and topstitching with a twin needle or zig-zag stitch. I chose not to hem mine because there isn’t a concern about swim knits fraying!
Turn both your peplum and bottoms right side out.
Slide your peplum over the top of your bottoms so that the waistline edges line up. Pin in place.
You can now finish the top edge of your bottoms as normal, just as described in the instructions. Either 1/4″ elastic or waistband. It’s the same process, you will just have an extra layer of fabric!
Then, of course, finish up your leg holes with elastic.
Ta-da!
LOOKING FOR MORE COTTESLOE or MINI COTTESLOE POSTS?
Here’s the full list of Cottesloe posts and tutorials:
- Pattern Tester Round-up
- Inspiration + Ideas
- Where to Buy Swimsuit Fabric
- View B Full Suit Construction (+ Optional Lining)
- View A Full Suit Construction with Shelf Bra and Ties
- Views C & D Bikini Construction
- Basic Elastic Insertion for All Views
- Waistband and Underband Elastic Insertion for Views C & D
- Bonus: Tie Strap Hack
We absolutely love seeing what you make, so don’t forget to tag your creations with #MNcottesloe and @megannielsenpatterns when sharing on social media, and check out what everyone else is up to!
