Sportswear and activewear: Materials, Specifications and Failure Risks

Recovery, opacity in a squat test and colour fastness to sweat. The third one is the one buyers forget.

Opacity in a squat test is the requirement buyers forget, and it is decided by cover factor rather than by weight. Two fabrics at the same gsm can differ visibly under stretch.

The second is colour fastness to sweat, which is a separate test from wash fastness and the one that produces complaints after a few wears rather than after a wash.

Requirements for activewear

• knitted fabric: Weight at 120-320 gsm — Apparel hand and opacity. A tolerance of +/- 5 % is workable on a stretch knit; +/- 10 % is a claim waiting to happen.
• swimwear fabric: Stretch at 4-way, 80-120 % elongation — Two-way stretch is cheaper and wrong for a one-piece.
• Service life: Recovery, opacity in a squat test and colour fastness to sweat. The third one is the one buyers forget.

Candidate materials for activewear, and where each one loses

A specification you can send for activewear

Knitted Fabric

Single jersey, 100 % combed cotton, 180 gsm +/- 5 %, open width 175 cm, stitch length 2.9 mm, shrinkage — that line covers the parameters that decide performance in this application. Adjust weight first if the requirement is unusual; it moves the price least and the outcome most.

Swimwear Fabric

80/20 nylon/spandex, 220 gsm, 4-way stretch, recovery >= 90 % after 5 cycles, chlorine-resistant spandex, UPF 50+, colour fastness to chlorinated water >= grade 4, Pantone 19-2430 TCX — that line covers the parameters that decide performance in this application. Adjust stretch first if the requirement is unusual; it moves the price least and the outcome most.

Failure patterns to test before committing to activewear

knitted fabric. Skew / torque: Side seams spiral after washing, garments twist on the body. Cause: high twist yarn, poor relaxation, or tubular fabric slit without rest. Test: AATCC 179 skew after home laundering, measure before and after.

swimwear fabric. Spandex degradation in chlorine: Swimsuits go limp and baggy after a season in a pool. Cause: standard spandex breaks down in chlorinated water; resistance is a polymer choice, not a finish. Test: ISO 105-E03 colour fastness plus retained elongation after 50 h chlorine immersion.

Sourcing notes for activewear

1. For knitted fabric that means structure at jersey / interlock / rib / fleece, not the nearest stock line.
2. Run the sample through the process your factory will use: shrinkage and skew are the whole game.
3. Check the MOQ per colour: 500-800 kg per colour for knitted fabric, 300-500 kg per colour or print for swimwear fabric.

Questions buyers ask before ordering

What is the actual tolerance behind activewear sourcing guide?

On activewear sourcing guide, tolerance of 120-320 gsm is what the line holds without special setup, which is why it is the standard quotation.

Can you hold tolerance at 120-320 gsm for activewear sourcing guide on a repeat order?

On activewear sourcing guide, below 120-320 gsm on tolerance the failure mode changes from appearance to function, and visual inspection stops helping.

What the first sample for activewear should prove

1. That structure sits inside jersey / interlock / rib / fleece on production material, not on a development sample.
2. That dimensional change passes after the process your factory will use, not only in the laboratory condition.
3. That the colour matches the approved standard under D65, on the actual knitted fabric lot that will ship.
4. That the packing and MOQ (500-800 kg per colour) match what the quotation assumed.

Sub-applications within activewear, and what each one needs

Certification class for activewear, by destination

Testing an activewear fabric before the first cut

Activewear is the category where a fabric that passes inspection still fails in use. The tests that predict it are cheap and rarely requested.

• Stretch and recovery, cycled. A single elongation reading says little. Five cycles to 80 % and back, measured at cycle one and cycle five, is what predicts bagging at the knee.
• Chlorine and sweat together. ISO 105-E03 covers chlorinated water; artificial sweat is a separate test. A fabric that passes one and fails the other is common in pool and gym programmes.
• Pilling at the seam. Martindale pilling on the flat is not the same as pilling where a coverstitch crosses a high-stretch zone. Test the seam, not the swatch.
• UPF after washing. UPF 50+ on the greige can drop after ten washes, especially on white and light shades, because the finish that provides it washes out.

For a first order, ask for the cycled recovery figure and the UPF after ten washes. Those two numbers separate a fabric built for activewear from a knit that was marketed into it.

Cut one garment before the bulk order and wash it five times. It costs a day and answers the question the lab report cannot.

Four performance figures, and the tests behind them

• Moisture management to AATCC 195, with a spreading speed above 3 mm/s on the face and a one-way transfer index that does not reverse after 20 washes.
• Pilling at grade 4 after 2 000 cycles Martindale on the brushed face, which is where a 150 gsm jersey separates from a 180 gsm interlock.
• UPF 50+ to AS/NZS 4399 at 160 gsm in a dark shade; the same fabric in white measures UPF 15-20 and cannot carry the claim.
• Elongation and recovery at 80 % extension with 90 % recovery after 5 cycles, which is what stops bagging at the knee.

Every one of these is a lab number with a method attached. A supplier who answers “moisture wicking” without the AATCC 195 result is describing a finish, not a performance.

Related reading

• What Swimwear Fabric Really Costs: A Line-by-Line Breakdown
• Inspecting Textile and Window Covering: Checkpoints, AQL and the Defects That Matter
• Cotton and T/C Fabric Guide: Yarn Count, Density and Shrinkage