Two-piece swimsuit for a girl: pattern, elastic, and bows
How to sew a two-piece swimsuit for a girl: draft the bottoms and top pattern, cut the pieces from stretch fabric, finish allowances, attach soft lingerie elastic, assemble the top, and sew on bows.
IntermediateFree
Translated
Things you will learn
The source swimsuit is sewn from stretch fabric using a drafted and printed pattern.
For the bottoms, the diagram gives formulas and sizes: top line from measurement minus 15 cm and minus 10%, height 22 cm, gusset 11 cm.
Choose soft lingerie elastic so it does not squeeze or rub wet skin.
The elastic is sewn slightly below the stitch line, gently stretched to create soft gathers.
Discussion-derived options include ties or straps for the bandeau top and ruffles for visual volume.
What you will make
The finished set includes bottoms and a top. It relies on soft elastic gathers and a decorative bow that pulls the top in at the center. The model is simple, but elastic comfort and top hold should be checked on the child.
Materials and tools
Materials
Stretch fabric, Main material for the bottoms, top, bow, and center loop.
Soft lingerie elastic, The source specifically asks for softer elastic so it does not squeeze or rub wet skin.
Thread, Choose thread matching the stretch fabric.
Drafted and printed pattern, The pattern diagram is shown in the source image.
Ribbon or cord for ties, Not part of the main tutorial, but the discussion suggests adding ties to the bandeau top.
Tools
Sewing machine, For straight stitching, attaching elastic, and finishing pieces.
Needle, For invisible stitches on the bow and center loop.
Pins, For holding hems, elastic, and pieces before stitching.
Scissors, For cutting fabric and trimming threads.
Iron, In the source, allowances are folded and pressed before stitching.
Preparation
Check the fabric and elastic
The swimsuit should stretch and recover. Use soft elastic: the source explicitly says it should not squeeze or rub wet skin.
Draft and print the pattern
The source uses a drafted pattern, not a ready downloadable file. Before cutting, check the measurements, the minus 10% formulas, and the control dimensions on the diagram.
Pattern
The diagram has separate pieces for the bottoms and top. The dimensions below are transferred from the source image as reference points, without adding new measurements.
Draft the bottoms from the diagram
The top line of the bottoms is built with this formula: measured length minus 15 cm, then minus 10%. The diagram also shows side sections of 3 cm each, height 22 cm, gusset 11 cm, narrow point 5 cm, and lower width 15 cm.
The diagram shows formulas and control measurements for the bottoms and top.
Do not remove the minus 10%
This accounts for fabric stretch. If you sew without checking stretch, the fit may turn out looser than needed.
Draft the top pieces
For the top, the diagram shows one piece at 1/2 chest circumference minus 10% with a 3–4 cm center dip, and another piece at 1/4 chest circumference minus 10%. The right piece also marks a height of 11 cm and an edge of about 5 cm.
Bottoms
Start with the swimsuit bottoms: side seams, folded allowances, elastic, and finishing.
Cut and stitch the two pieces
Cut two bottom pieces from stretch fabric and sew the side seams.
Fold and stitch the allowances
Fold the allowances to the wrong side, press, and sew a straight stitch to hold the fold.
Sew on the lingerie elastic
Place the lingerie elastic slightly below the stitch line. Gently stretch the tape as you sew it to the fabric so it forms soft gathers.
The elastic is sewn slightly below the stitch line while gently stretched.
Do not overtighten the elastic
The elastic should gather the fabric but not dig into the skin, especially when the swimsuit is wet.
Finish the side allowances
After attaching the elastic, finish the side seam allowances. The base of the bottoms is ready.
Top and bows
The top is finished in a similar way: folded edges, elastic, joining seam, and a decorative bow with a center loop.
Finish the long edges of the top
Fold the long edges to the wrong side, press, and stitch. Then place the elastic and stitch it to the fabric, stretching it gently.
Join the top seam
Sew the top seam and finish the raw edges so they do not fray or rub.
Sew the bow
Cut a rectangular piece. Fold it in half lengthwise with right sides together, then sew one long side and one short side. On the second short side, stop the seam so there is an opening for turning. Turn the piece right side out and close the opening with an invisible stitch.
The top is finished in a similar way, then a decorative bow is sewn.
Make the center loop
Fold the loop piece in half right sides together, stitch along the long side, and turn it right side out.
Gather the top with the bow and decorate the bottoms
Wrap the loop around the bow, catching the top, and sew the loop edges with an invisible stitch. Sew the small bow to the upper back of the bottoms in the same way.
Final assembly: the bow gathers the top at the center, and a small bow is sewn to the bottoms.
Finish and variations
Finish
Do a fitting after assembly
Check that the elastic does not squeeze, the side edges do not flare, and the top does not slide down. A child’s swimsuit should hold softly, without harsh tension.
Ruffles for a very slim figure
The discussion notes that ruffles can work for a very slim girl: they decorate the set and visually add volume. This is an optional variation, not part of the main tutorial.
Variations
Ties or straps for the top
A comment warns that a bandeau top on a flat chest may not hold for long. A practical option is to add center ties or tank-top-style straps.
More soft gathering
If you want the bottoms to look fuller, use the elastic gathers and ruffles carefully, while keeping the elastic soft.
After fitting, the elastic leaves a mark or feels uncomfortable.
Likely cause
The lingerie elastic is too firm or was stretched too much while sewing.
How to fix it
Use softer elastic and sew it with light, not strong, tension. This directly follows the source warning about wet skin.
The bandeau top does not hold well
Problem
The top slides down or stays in place only while the child stands still.
Likely cause
On a flat child’s figure, a strapless top may be unstable.
How to fix it
The discussion suggests adding ties: at the center or as tank-top-style straps. Decide this during fitting instead of relying only on the bandeau.
The edge became wavy
Problem
After stitching with elastic, the edge looks twisted or wavy.
Likely cause
The elastic was stretched unevenly, or the fabric stretched under the presser foot.
How to fix it
Test the tension on a scrap of the same fabric before sewing the real piece. Stretch the elastic evenly and do not stretch the fabric more than needed.
The bow looks bulky
Problem
The loop and bow create a thick knot on the top.
Likely cause
The turning opening was closed roughly, or the fabric was folded too thickly.
How to fix it
Leave enough room for turning and close the opening with an invisible stitch, as in the source. Shape the bow corners before sewing it on.
The fit differs from the diagram
Problem
After assembly, the swimsuit is looser or tighter than expected.
Likely cause
The fabric stretch differs from the fabric assumed by the minus 10% pattern formula.
How to fix it
Check the stretch first and fit before the final trim. Treat the pattern formulas as a base, not a guarantee of identical fit on every fabric.
?FAQ
What fabric should I use for a child’s swimsuit?
The source specifies stretch fabric. It should stretch, recover its shape, and not feel rough against wet skin.
What elastic should I use?
Use soft lingerie elastic. The author specifically warns to choose softer tape so it does not squeeze or rub wet skin.
What measurements are shown for the bottoms pattern?
The diagram shows the top line formula “measurement length - 15 cm - 10%,” height 22 cm, gusset 11 cm, narrow point 5 cm, lower width 15 cm, and side sections of 3 cm each.
How is the top drafted?
The diagram drafts the top from chest circumference: one piece is 1/2 chest circumference minus 10% with a 3–4 cm dip, and the other is 1/4 chest circumference minus 10%, with height 11 cm.
Does the bandeau need ties?
The main tutorial has no ties, but the discussion suggests adding them: at the center or like a tank top. This helps if the bandeau does not hold well.
How do I finish the bow neatly?
After turning the rectangular piece, close the remaining opening with an invisible stitch. Close the loop around the bow with an invisible stitch too.
Your project
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