Nylon Yarn for
Activewear.

GSM Range

• Lightweight sports bras, under-layers: 150–180 GSM • Standard activewear (leggings, shorts, training tops): 180–220 GSM • Compression tights and supportive garments: 220–270 GSM • Swimwear-crossover and multi-sport constructions: 200–240 GSM Nylon is typically specified at a higher GSM than polyester for equivalent applications because the additional weight delivers better compression and more substantial hand feel. Avoid sub-150 GSM nylon-spandex knits for leggings — opacity becomes an issue and fabric integrity is marginal.

Yarn Count

• Fine denier nylon (sports bras, liners): 20D–40D semi-dull or bright, 24–34 filaments • Standard activewear (leggings, shorts): 40D–70D, 34–68 filaments • Heavier compression: 70D–140D, 48–136 filaments • Spandex component: 20D–40D bare or covered spandex (Lycra or equivalent)

Knit Construction

• 4-way stretch interlock: Industry standard for leggings and compression — even structure, minimal runs, good compression • Single jersey (nylon-spandex): Lighter training tops, sports bra inner layers • Warp knit (tricot, Raschel): Swimwear-crossover, high-elasticity performance fabrics — requires different machinery than circular knitting • Seamless circular: Growing category; nylon's stretch recovery makes it excellent for seamless constructions

Shrinkage

• Nylon 6 knit: 3–5% length, 2–3% width after first wash at 40°C • Nylon-spandex interlock: 4–6% length without heat setting; < 2% after proper heat setting at 170–180°C Heat setting is non-negotiable for nylon-spandex activewear. Confirm heat-setting temperature with your mill — nylon 6 heat-sets at 170–185°C (vs polyester at 180–190°C). Skipping heat setting is the single most common cause of size complaints on nylon leggings.

Pilling Resistance

• Nylon filament (warp or circular knit): 4–5 on Martindale scale • Nylon-spandex interlock (standard): 4 • Micro-denier nylon (< 1 dpf): 3–4 (finer filaments break more easily at surface, slightly more visible pilling than coarser grades)

Colorfastness

• Wash fastness (ISO 105-C06): 4–5 (acid dyes on nylon) • Light fastness (ISO 105-B02): 3–4 — this is a genuine limitation vs polyester's 5–6 • Rubbing fastness dry: 4–5; wet: 3–4 • Chlorine-water resistance (relevant for swimwear crossover): Specify chlorine-resistant spandex component; nylon fibre itself is moderately chlorine-resistant

Tensile Strength

• Nylon 6 filament: 40–55 cN/tex • Nylon 66 filament: 50–65 cN/tex • Nylon-spandex interlock (fabric level): Warp 180–250 N, Weft 150–220 N (ASTM D5034)

MOQ Guidance

• Standard 4-way stretch nylon-spandex interlock: 800–1,500 kg per colour (higher than polyester due to smaller mill base) • ECONYL-based construction: 1,000–2,000 kg minimum (Aquafil supply chain typically requires scale commitments) • Fine denier nylon for sports bras (< 30D): 500–800 kg • Warp knit constructions: 2,000–3,000 kg (specialist mills, longer setup)