Manufacturer · Fashion Accessories
A good swimwear elastic must withstand chlorine, salt water, sun and sunscreen without losing its stretch. The most widely used are rubber elastic, knitted elastic with chlorine-resistant elastane and clear polyurethane elastic. A width of 6–10 mm is usually chosen for the leg openings and neckline and up to 20 mm for the lower edge of the top, and the elastic is sewn into the hem with a coverstitch or zigzag.
Why ordinary elastic is no good for swimwear
The elastane (spandex) in ordinary elastic is broken down by the chlorine in swimming pools and by UV rays. After one or two seasons the swimsuit elastic slackens, the leg openings come away from the body and the neckline gapes. White, "crinkled" areas appear on the surface – a sign that the elastic yarns have broken. That is why swimwear and swimming costumes use elastics developed for contact with water.
Types of swimwear elastic
| Type | Properties | Suitable for |
|---|---|---|
| Rubber elastic (with or without a textile cover) | Very good resistance to chlorine and salt water, strong recovery | Classic swimsuits, swimming costumes, leg openings and necklines |
| Knitted elastic with chlorine-resistant elastane | Soft, smooth, easy to sew | Fashion swimwear, bikinis, inner edges |
| Clear polyurethane elastic | Thin, invisible, light | Stabilising shoulders and necklines, thin edges |
| Silicone gripper elastic | Stays in place without pressure | Strapless tops, beach dresses |
Rubber elastic is the traditional choice for swimwear – it contains no elastane for chlorine to break down. When the technical description says "chlorine-resistant", check what test and what load it refers to and ask for a sample. You will find the different types of elastics for clothing in the elastics category.
Swimwear elastic widths by zone
- Leg openings of briefs: 6–10 mm.
- Neckline and armholes: 6–10 mm.
- Waist of briefs: 8–12 mm.
- Lower edge of a bikini top: 10–20 mm – it carries a greater load.
- Straps: 6–10 mm, sewn into turned fabric.
- Men's swim shorts: 25–40 mm at the waist, usually in a channel with a drawcord.
How much to stretch the elastic
Swimwear elastic is sewn on under tension so that the edge hugs the body and does not gape when wet. Wet fabric becomes heavier and slackens, so the tension is slightly greater than with underwear. The usual practice is:
- front of the leg opening – minimal tension, the elastic almost just follows the edge;
- back of the leg opening – stronger tension, for good coverage and so that it does not ride up;
- neckline – light tension along the whole length, stronger at the deepest part;
- lower edge of the top – stronger tension for support.
The exact values are determined by testing and depend on the fabric and the elastic.
How swimwear elastic is sewn
- Place the elastic along the edge on the wrong side of the fabric.
- Catch it with a zigzag or overlock, stretching the elastic according to the zone.
- Turn the edge inwards so that the elastic is completely covered by the fabric.
- Topstitch with a coverstitch, triple zigzag or twin needle.
Threads and needles
Use a polyester or polyamide thread that withstands chlorine and does not rot, and a stretch needle for elastic fabrics. Ordinary cotton thread is not suitable for swimwear – it loses strength from moisture. You will find suitable threads in the threads category.
Knitted elastic for swimwear – when it is suitable
Soft knitted elastic is easy to sew and pleasant against the skin, but it must have chlorine-resistant elastane if the swimsuit is for the pool. For fashion swimwear worn mainly on the beach it is a frequently used choice. For training swimming costumes worn almost every day in chlorinated water, rubber elastic is the safer option.
Swimwear care
- rinse the swimsuit in clean lukewarm water straight after the pool or the sea;
- wash by hand or on a delicate programme up to 30 °C;
- do not wring hard or twist;
- dry flat in the shade;
- do not leave a wet swimsuit in the sun or on hot surfaces;
- avoid the tumble dryer.
Sunscreens and oils also strain the elastic – rinsing after use extends its life.
Common mistakes with swimwear
- Ordinary elastic with elastane in a swimsuit for the pool – it slackens after one season.
- Too wide an elastic on the leg openings – the edge is stiff and cuts in.
- The same tension along the whole length – the leg opening rides up at the back.
- Cotton thread – the seams rot and break.
- An elastic not completely covered by the fabric – rubbing and rapid wear.
Colour and visibility of the elastic
In swimwear the elastic is usually hidden in the hem, so its colour matters mainly with light and thin fabrics. A white elastic under a dark fabric or a black one under a light fabric can show through, especially when the swimsuit is wet. Choose an elastic in tone with the fabric, or beige for light styles. On swimsuits with contrasting bindings the elastic can also be a visible element – then its colour and surface must be coordinated with the design, and the elastic must be resistant to fading from sun and chlorine.
Swimwear elastics from Polkom
Polkom is a Bulgarian manufacturer and wholesaler of clothing haberdashery based in Sofia. We supply elastics for underwear and swimwear, knitted and woven, in various widths and colours, with samples for testing and delivery throughout the EU. Minimum quantities depend on the article. Send us a description of the style and the conditions of use via our contact page so that we can suggest a suitable elastic.
