What makes a fabric suitable for swimwear
A swimsuit needs to stretch in at least one direction, recover its shape, dry quickly and handle water, sun and often chlorine. For that reason swim fabrics are knits made from synthetic fibers blended with elastane (also sold as spandex or Lycra). Most swim patterns are written for fabrics with good stretch and recovery, so check the pattern’s recommended stretch percentage and fabric type before buying.
Types of swimsuit fabric
Nylon-spandex
Nylon blends are a common choice for swimwear and are often described as smooth, soft and stretchy (see is nylon fabric stretchy and is nylon good or bad). A frequently quoted composition is mostly nylon with a smaller share of spandex, but exact proportions vary by fabric, so go by the pattern and the seller’s description.
Polyester-spandex
Polyester blends are also widely sold for swimwear (see does polyester material stretch for how much give to expect). Many sellers describe them as durable and resistant to chlorine, though results depend on the particular fabric and how it is cared for. The feel can differ from nylon, so order a sample if you are unsure.
Recycled and specialty swim fabrics
Some suppliers offer swim fabrics made with recycled fibers, as well as textured, printed and metallic options. They are used the same way as standard swim knits, but check each product’s stretch and recovery.
Lining and support
Most swimsuits are lined, particularly in light colors, to prevent show-through and add some support. Swim lining is a lightweight stretch fabric designed for this purpose. Power mesh is sometimes used for extra support in certain areas. Your pattern will say whether lining is needed and where.
Choosing stretch and direction
Look for fabric described as four-way stretch, meaning it stretches along both the length and the width. Patterns normally state the direction where the most stretch should go, which is usually around the body. Cut accordingly. If you want the background on why knits stretch while many other cloths do not, see our article on whether woven fabric is stretchy.
Needles, thread and stitches
- Needle. A ballpoint or stretch needle helps avoid snags and skipped stitches. Choose a size suited to the fabric weight, with small sizes commonly used for swim knits.
- Thread. Polyester thread is commonly recommended for strength and flexibility. Some people use woolly nylon in sergers or for finishing.
- Stitch. Use a zigzag or other stretch stitch so seams stretch with the fabric. A plain straight stitch can pop when the garment is stretched.
- Test first. Sew a scrap and stretch the seam before working on the real pieces.
Elastic
Use elastic made for swimwear, which is designed to hold up to water and, depending on the type, chlorine. Standard sewing elastic can deteriorate faster. Your pattern will suggest widths and lengths, and a test on scrap fabric helps you get the tension right.
Cutting and sewing tips
- Cut in a single layer so the slippery fabric does not shift, using a rotary cutter and pattern weights if possible.
- Pay attention to grainline and stretch direction.
- Use clips instead of pins if pins leave visible holes.
- Finish seams with a stretch-friendly method, such as a serger or a zigzag.
- Press carefully with a low heat setting and a pressing cloth, since synthetic fibers can melt.
- Topstitching, such as a twin needle or a zigzag, can add a neat finish while keeping stretch.
How much fabric do you need
There is no single answer. Yardage depends on the pattern, the size, the style of suit and the fabric width, and it is listed on the pattern envelope or instructions. Because swim fabric is often sold in narrower or wider widths, check the chart for your width.
Is sewing swimwear hard
It is often easier than people expect, because swimsuits use small pieces of fabric. The challenges are handling stretchy cloth and applying elastic evenly. Many makers start with a simple style and practice on scraps. Practicing your technique on a basic knit first can help, and you can read how to prep fabric in our guide to preparing fabric for sewing.
Care for swimsuit fabric
Rinse your suit in cool water after use, wash gently and avoid high heat, which can damage elastic. Follow the fabric supplier’s care instructions, since recommended methods differ.
Frequently asked questions
What kind of fabric should I use to sew a swimsuit?
A four-way stretch knit made from nylon or polyester blended with spandex, usually with a swim lining.
What is the best fabric for swimwear?
There is no single best. Nylon-spandex and polyester-spandex are the common choices, and the right one depends on the feel you want and how much sun or chlorine exposure to expect.
Does swimsuit fabric shrink?
It can change slightly, depending on the fabric. Synthetics generally shrink little, as covered in do synthetic fabrics shrink. Follow the seller’s advice and check a small swatch.
Can I use regular thread?
Polyester thread is generally recommended over thread with no give, such as some cotton threads.