Making your own swimwear is one of the most rewarding sewing projects — and one of the most technically demanding. The difference between a swimsuit that holds its shape through an entire pool season and one that stretches out, fades, or deteriorates after a few washes comes down almost entirely to fabric choice. At Stretchhouse, we carry the fabrics that professional swimwear designers, competitive swim teams, and experienced home sewists rely on.
What Makes a Great Swimwear Fabric?
Not every spandex fabric is appropriate for swimwear. The unique demands of a swimsuit — constant water exposure, UV radiation, chlorine or salt, stretched across a body during movement — require specific properties: chlorine resistance (nylon spandex is significantly more resistant than polyester), UV resistance, quick-drying construction, stretch and recovery that maintains a fitted silhouette, opacity when wet, and color retention through chlorine exposure.
Best Swimwear Fabrics at Stretchhouse
| Fabric | Best Use | Chlorine Resistance | Feel |
|---|---|---|---|
| Milliskin Matte | Competitive swimwear, racing suits | Excellent | Smooth, firm |
| Milliskin Shiny | Fashion swimwear, team suits | Excellent | Smooth, glossy |
| Supplex Spandex | Recreational swimwear, rash guards | Very Good | Soft, athletic |
| Power Mesh | Swimsuit lining, bodice support | Good | Firm, supportive |
| Tricot Lycra Shiny | Fashion swimwear, cover-ups | Good | Drapey, shiny |
Nylon vs. Polyester Spandex for Swimwear
For swimwear used in chlorinated pools, nylon spandex is the clear choice. Nylon fiber is naturally more chlorine-resistant than polyester — it maintains elasticity, color vibrancy, and structural integrity significantly longer in pool environments. This is why competitive swimwear, from high school team suits to Olympic racing suits, is almost universally nylon spandex. For beach and outdoor use where UV exposure is the main concern, polyester spandex is a reasonable alternative.
Milliskin: The Gold Standard for Competitive Swimwear
Milliskin Matte (80% Nylon / 20% Spandex, 210 GSM, 60″ wide) is the most widely used swimwear fabric in competitive aquatic sports. The tight knit construction creates a fabric that glides through water, resists chlorine degradation, holds bright color, and maintains shape through intensive athletic use. Milliskin Shiny has the same specs with a high-gloss surface — used in fashion swimwear, synchronized swimming, and performance swimwear where visual impact matters. For fashion swimwear and cover-ups with a luminous finish, our Sheer Iridescent Opalite fabric is a striking option.
Power Mesh: The Essential Swimwear Lining
Power mesh is the fabric you never see — but it’s doing critical work inside almost every quality swimsuit. This dense, firm, 4-way stretch mesh is used as a lining layer inside swimsuit bodices, bra cups, and structured panels. It provides support, shape retention, additional opacity (especially important for lighter-colored swimsuit fabrics), and the structure that helps a swimsuit maintain its shape while wet. For one-piece swimsuits, use power mesh as a full inner lining. For bikini tops, use it to line the cups.
How Much Swimwear Fabric Do I Need?
| Garment | Main Fabric | Power Mesh Lining |
|---|---|---|
| Bikini top only | 0.5 yards | 0.25–0.5 yards |
| Bikini bottom only | 0.5 yards | 0.25 yards |
| Full bikini set | 0.75–1 yard | 0.5–0.75 yards |
| One-piece (adult XS–L) | 1.5–2 yards | 0.75–1 yard |
| One-piece (adult XL–2XL) | 2–2.5 yards | 1–1.25 yards |
| Short-sleeve rash guard | 1–1.25 yards | Not required |
| Long-sleeve rash guard | 1.5–1.75 yards | Not required |
Always add 10–15% for cutting errors. For children’s sizes, reduce adult estimates by 40–60% depending on measurements.
Frequently Asked Questions
What is the best fabric for making swimwear?
For most swimwear applications, 80/20 nylon spandex is the best choice. Our Milliskin Matte and Milliskin Shiny fabrics (80% Nylon / 20% Spandex, 210 GSM) are the most widely used swimwear fabrics in competitive aquatic sports. For recreational swimwear where UV protection is a priority, Supplex Spandex is an excellent alternative.
Is nylon or polyester better for swimwear?
For chlorinated pool use, nylon spandex wins clearly. Nylon is significantly more chlorine-resistant than polyester — it holds elasticity and color longer in pool environments. Polyester spandex is more UV-resistant, making it reasonable for beach and outdoor use. For competitive swimming, always choose nylon.
How much fabric do I need to make a swimsuit?
For a basic one-piece swimsuit in adult sizes XS–L, plan for 1.5–2 yards of main fabric plus 0.75–1 yard of power mesh for lining. For a bikini set, plan for 0.75–1 yard of main fabric plus 0.5 yards of power mesh lining.
Do I need to line swimwear fabric?
For one-piece swimsuits and structured bikini tops, yes — lining with power mesh significantly improves opacity, shape retention, and durability. If your main fabric has any transparency when stretched, lining is essential.
Further reading: Sewing Your Own Swimsuit Guide | Nylon vs. Polyester Spandex | Fabric Yardage Guide