Open-Back Swimsuit
At last, we’re bringing you a tutorial you’ve requested again and again: a swimsuit! We’re starting with a classic—an open-back swimsuit with low-cut leg openings that’s comfortable for playing at the beach or pool. You’ll see that it’s easier to sew than you might think.
Project preview
This video is for members
Join Lulu Ferris to watch the complete class and sew along at your own pace.
What you’ll make
Sew a classic one-piece swimsuit with low-cut leg openings and a deep open back.
The shape is designed as a comfortable option for moving and playing at the beach or pool.
A front swim lining provides coverage, while the elasticized openings keep the suit close to the body.
What you’ll learn in this class
- Test stitch settings and needles before sewing swim Lycra.
- Join the two back pieces and enclose the front lining at the crotch.
- Sew stretch seams with a straight stitch plus zigzag, elastic stitch or overlocker.
- Measure and join elastic loops for the leg openings.
- Quarter the elastic and garment openings for even distribution.
- Apply elastic while stretching it gently between matching points.
- Turn and topstitch the elasticized edges so they lie flat.
Fabric and materials
Use swimwear Lycra and swim lining. A firmer Lycra gives the body more compression and support than a softer fabric.
Virgin rubber swim elastic is preferred for greater resistance to salt, sun, chlorine and repeated stretching.
The class uses ordinary 1 cm elastic to show that it can work, while explaining that it may not last as long as swim-specific rubber elastic.
A stretch needle is recommended. The instructor also demonstrates alternatives for anyone sewing without an overlocker.
Sizing
The downloadable pattern includes women’s sizes S, M, L, XL and XXL.
If you need help assembling a tiled pattern, use the PDF sewing pattern guide.
The class includes the downloadable LFM21 pattern and methods for sewing the swimsuit with either a standard machine or an overlocker.
Pattern & materials
Patterns are included with membership
Active members can download every available PDF and materials list.
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