Nylon Yarn for
Underwear & Basics.

GSM Range

• Thongs and minimal coverage: 100–130 GSM • Briefs, bikinis, hipsters (standard): 130–160 GSM • High-waist shaping briefs and boyshorts: 160–200 GSM • Bralettes and wireless bras: 140–180 GSM (body panel), 200–240 GSM (band/support zones) • Thermal / mid-weight basics: 180–220 GSM Below 120 GSM, fabric integrity and opacity become problematic without tight interlock construction. Above 200 GSM in underwear, the garment becomes perceptible under clothing — contradicting the no-show positioning most nylon underwear is sold on.

Yarn Count

• Standard microfibre underwear body: 70D/68F (1.0 dpf) — balanced cost and softness • Premium no-show underwear: 70D/144F (0.5 dpf) — maximum smoothness, 15–20% price premium • Budget microfibre: 70D/34F (2.0 dpf) — noticeably coarser, not appropriate for skin-contact underwear • Spandex component: 20D–40D bare spandex for body panels; 20D–40D covered spandex for waistbands • Nylon-spandex ratio: 78–82% nylon, 18–22% spandex (standard); 75/25 for shaping/compression styles

Knit Construction

• Four-way stretch interlock: Standard for seamless-look cut-and-sew briefs and bralettes — smooth face, dimensional stability, opacity • Seamless circular knit (Santoni): Premium seamless underwear, no seams required — requires dedicated machines • Warp knit / tricot: Used in flatback bra bands and some brief panels for stability without stretch • Single jersey: Lightweight sleep shorts and basics — less opaque, lower cost, simpler construction

Shrinkage

• Nylon filament: 2–4% length, 1–2% width after first wash at 30°C • Nylon-spandex: 3–5% length depending on heat setting • Critical: Heat set at 165–175°C for 25–35 seconds. Under-set nylon-spandex underwear will shrink unevenly in consumer wash, generating complaints about fit change at first wash.

Pilling Resistance

• Filament nylon interlock: 4–5 on Martindale scale • At leg-opening edges and waistband interface: 3–4 on extended testing (> 5,000 cycles) • Finished seam areas: 3–4 depending on stitching method

Colorfastness

• Wash fastness (ISO 105-C06) at 40°C: 3–4 (acid dyes, standard); 4–4.5 achievable with metallic complex dyes on dark shades • Light fastness (ISO 105-B02): 4–5 on dark shades, 3–4 on white/pastel (UV yellowing risk) • Rubbing fastness (dry): 4–5; (wet): 3–4 • Note: Nude, blush, and skin-tone shades — critical for no-show commercial value — require careful dye formulation to avoid the pinkish or orange cast that appears on nylon with suboptimal acid dye combinations. Lab-dip approval on skin-tone shades takes additional rounds.

Tensile Strength

• Nylon filament: 40–75 cN/tex • Fabric burst strength (appropriate for knit underwear): 200–350 kPa (ASTM D3786) • Seam strength (flatlock or coverstitch): 120–180 N at crotch gusset and waistband attachment

MOQ Guidance

• Standard nylon-spandex interlock (stock yarns): 500–800 kg per colour • Seamless full-package garments: 500–1,000 pieces per colourway, style-dependent • ECONYL recycled nylon: 1,000–2,000 kg minimum (limited mill base) • Skin-tone/nude colourways: Often require separate dye lots — MOQ applies per shade, not per colourway family