Everything You Need to Know Before Sewing Your Own Swimsuit: Complete Guide

There are several important things to consider when making your own swimsuit.

Here are our tips and tricks to help you choose the right fabrics, accessories, and techniques for successful sewing projects. Get your sewing machines ready — the world of swimwear will soon hold no secrets for you!

Good news: sewing swimwear is much more accessible than you might think. As soon as you feel comfortable with your sewing machine, you can get started. Contrary to popular belief, you don’t need a serger or coverstitch machine — a short and narrow zigzag stitch is all you need for a durable and stretchy result.

Johanne-Julie shares all her tips and tricks, from choosing the right fabric to sewing elastic, making straps, and hiding elastic inside the lining.

Lycra®, spandex, elastane… have you heard these terms before? It’s easy to get confused.

Elastane is the term used in Europe, while spandex is the North American term. Lycra®, on the other hand, is a trademark owned by DuPont™. It’s similar to how we use the word “Kleenex” for tissues!

For more details, check out our full article dedicated to Lycra®.

When choosing fabric for swimwear, we recommend a composition of about 80% nylon and 20% spandex.

This blend offers several advantages:

• Nylon is strong and durable

• Spandex provides stretch and flexibility

• The fabric dries quickly because it absorbs very little water

Make sure your fabric is 4-way stretch, meaning it stretches both lengthwise and crosswise.

Most swimwear fabrics are also designed to resist fading caused by UV rays and chlorine.

Nasha introduces our two exclusive swimwear fabrics:
the Amalfi nylon knit and the Maui boardshort fabric, along with their key features.

Amalfi nylon knit

Maui boardshort fabric

Printed swimwear knits

Choosing the right lining is essential when making a swimsuit.

Two main options are available:

• Nylon knit

• Polyester knit

These fabrics are usually 2-way stretch.

• For a one-piece swimsuit, place the stretch vertically (along the body)

• For a two-piece swimsuit, you can use the stretch horizontally

Linings are typically available in beige or black.

Tip: For white swimsuits, a slightly bluish lining helps prevent transparency when wet.

If you’re looking for more support and shaping, consider using a denser lining for a smoothing effect.

Depending on your needs, several types of elastic can be used in swimwear construction:

• Rubber elastic

• Clear elastic (Mobilon)

• Cotton elastic

• Brushed elastic (often called “plush elastic”)

Rubber and clear elastics are ideal because they are chlorine-resistant and quick-drying.

Brushed elastic is especially appreciated for its softness against the skin.

Installation tips:

• Sew the elastic onto the lining with the soft side facing the skin

• Use about 1/8 less than the total length for proper tension

If you don’t have a coverstitch machine, a zigzag stitch works perfectly.

To complete your project, a few accessories can make all the difference:

• Rings

• Sliders

• G-hooks

These elements allow you to adjust straps and achieve a professional finish while ensuring comfort and durability.

Discover our full selection of swimwear accessories

Working with stretch fabrics requires a few specific tools and techniques.

• Recommended scissors
We recommend the KAI 7250 SE tailor scissors (10”), ideal for cutting lightweight and stretch fabrics with precision.

• Sewing machine needles
Use needles designed for stretch fabrics, such as:

• Stretch needles

• Jersey needles

For a pro look, you can also use twin needle.

• Pins vs clips
Unlike other sewing projects, we do not recommend using clips. Stretch fabrics tend to slip, which can affect accuracy. Pins are a better option to keep your fabric in place.

• Sewing technique
No special equipment needed:

• A short, narrow zigzag stitch allows the fabric to stretch

• A regular sewing machine is more than enough

There are different sizes and shapes of cups and underwires:

• Half cups

• Full cups

Usually made of nylon, cups dry quickly and can be easily adjusted. You can trim them to perfectly fit the shape of your swimsuit.

Soft against the skin, they help shape the bust. For additional support, you can add underwires.

Important: underwires should never be in direct contact with the skin. You’ll need to create a casing.

We recommend sewing the casing flat first, making it easier to insert the underwire afterward.

Explore our full selection for swimwear making

To extend the life of your swimsuit:

• Wash on a delicate cycle

• Avoid twisting the fabric

• Let it air dry

Tip: Always rinse your swimsuit after swimming in a pool or the ocean to remove chlorine or salt.

The most recommended fabric is a blend of about 80% nylon and 20% spandex. It offers excellent stretch, dries quickly, and resists chlorine and UV rays.

Yes, absolutely! A standard sewing machine is enough. Use a short, narrow zigzag stitch to maintain stretch. A serger or coverstitch machine is helpful, but not required.

For best results, use:

• a stretch needle

• or a jersey needle

These prevent damage to elastic fibers.

Not recommended. Stretch fabrics tend to slip with clips. Pins provide better control and precision.

Yes, in most cases. A lining:

• improves comfort

• prevents transparency

• provides better support

This can be caused by:

• machine drying

• prolonged exposure to chlorine or salt

• improper care

Always rinse your swimsuit after use and air dry it to extend its lifespan.

Now that you have all the information you need to create your own swimsuit, all that’s left is to get started!

Have you ever sewn a swimsuit, or are you thinking about trying it? Share your projects or questions with us!

If you’d like, share your creations on social media using #thefabricclub.