# Spandex Yarn for Athleisure **Fiber Guide · B2B Sourcing · Data-Driven** ## Spandex / Elastane Yarn for Athleisure. Spandex — sold as Lycra (Invista), ROICA (Asahi Kasei), or Creora (Hyosung) — is the functional backbone of every high-performance athleisure garment. At 2–20% of total fabric composition, it delivers 500–800% elongation and near-complete elastic recovery, enabling the second-skin fit that leggings, joggers, and yoga tops demand. No other fiber achieves this stretch-to-recovery ratio at this weight. The critical differentiator for athleisure versus sportswear proper: athleisure fabrics must hold dimensional stability through repeated wear and laundering at body temperatures, not just during a single session. Spandex core yarn bare or covered with nylon or polyester determines the hand feel, opacity, and longevity of your final fabric — and getting that combination right is where sourcing decisions matter. --- ## At a Glance **The fiber–application fit, summarised.** | Dimension | Rating | Why | |---|---|---| | Softness / Hand Feel | 8/10 | Spandex itself is smooth and non-abrasive, but hand feel is primarily driven by the covering fiber (nylon feels silkier, polyester feels cooler but slightly rougher). Bare spandex is tacky and never used alone. | | Durability / Abrasion Resistance | 7/10 | Covered spandex in athleisure fabrics performs well against seam stress and repetitive stretch — typical legging construction survives 100+ wash cycles with minimal degradation when core yarn count is correctly specified. Bare spandex degrades under chlorine, UV, and heat above 150°C. | | Colour Retention / Colorfastness | 7/10 | Spandex accepts disperse dyes reasonably well in polyester-spandex blends. Nylon-spandex fabrics require acid dyes at lower temperatures. Both achieve ISO 105-C06 wash fastness grade 4–4.5 in standard conditions. | | Breathability / Moisture Management | 6/10 | Spandex contributes negligibly to moisture transport — all breathability comes from the covering fiber and knit structure. Dense interlock constructions can feel occlusive; open-mesh or texture-loop structures compensate. | | Stretch & Recovery | 10/10 | This is the entire reason spandex exists. 500–800% elongation at break, with recovery force sufficient to maintain compression. At 15–20% spandex content in a legging, you get the 4-way stretch required for yoga and squat-proof performance. | | Cost Efficiency | 6/10 | Spandex adds ₹80–150 per kg to fabric cost depending on denier and brand. For athleisure, this is unavoidable — no alternative delivers comparable stretch recovery without spandex. Cost-per-wear improves significantly when fabric maintains shape retention across 50+ cycles. | | Sustainability / Eco Credentials | 4/10 | Conventional spandex is 100% synthetic (polyurethane), petroleum-derived, and non-biodegradable. Recycled content options exist (ROICA V550, Lycra EcoMade) but command a 25–40% price premium. End-of-life recycling of blended spandex fabrics remains commercially unresolved. | | Ease of Care / Wash Durability | 7/10 | Machine washable cold, avoid high heat (tumble dry low or air dry). Chlorine bleach destroys spandex — this must be communicated to end consumers. Correctly covered yarns maintain stretch recovery for 80–100 washes in lab conditions. | --- ## Why Spandex for Athleisure **What makes spandex the right choice for athleisure garments.** **01. Second-Skin Fit Mechanics** The defining performance requirement of athleisure leggings and yoga pants is that the fabric conforms to body contours through a full range of motion without sagging, bagging, or restricting movement. This requires a fabric that can stretch 60–100% in both directions simultaneously (true 4-way stretch) and return to its original dimensions with force. Spandex achieves this through its polyurethane polymer chain structure — long, coiled molecular segments that extend under tension and recoil elastically when released. At 15–20% spandex content in a nylon-spandex or polyester-spandex knit, the fabric exhibits recovery forces of 0.8–1.2 N/cm², enough to maintain contact with the body during dynamic movement without the "fall down" effect that plagues lower-stretch constructions. Compare this to conventional elastomeric alternatives: rubber yarn tops out at 300% elongation and has poor heat stability; PTT (polytrimethylene terephthalate) bicomponent yarns offer stretch recovery in one direction only. For multi-directional stretch in athleisure, spandex remains the only commercial solution at scale. **02. Opacity Engineering in Leggings** Squat-proof opacity is a non-negotiable for premium athleisure, and it is a function of fabric construction and fiber choice — not simply GSM. A 200 GSM polyester-spandex fabric can fail opacity tests while a correctly engineered 160 GSM nylon-spandex fabric passes. The variables are: denier of the covering yarn, knit loop geometry, and spandex draw ratio during knitting. Nylon covering yarns at 40D–70D in circular knit interlock constructions produce tighter loop geometry than equivalent polyester yarns, reducing the inter-yarn gap that creates opacity failures. Spandex draw ratio (how much the core yarn is stretched during knitting) controls the final stitch density — a higher draw ratio (3.5:1 to 4:1) produces a denser, more opaque fabric. For sourcing teams specifying legging fabrics: request opacity test results using the AATCC standard test method with a minimum 80% opacity retention at 60% stretch. Many suppliers will test opacity flat but not under tension — the latter is the relevant condition. **03. Fashion-Forward Hand Feel: Nylon-Spandex vs Polyester-Spandex** Athleisure sits at the intersection of performance and fashion, and fabric hand feel directly drives brand positioning and retail price point. The choice between nylon-spandex and polyester-spandex is the primary determinant of hand feel in this category — not fiber processing or finishing alone. Nylon-spandex (typically 80/20 nylon-spandex) delivers a silkier, more luxurious hand feel owing to nylon's smoother filament surface and lower coefficient of friction against skin. The fabric feels "premium" — this is why Lululemon Align, Athleta, and comparable $80–$150 leggings use nylon-spandex. The tradeoff: nylon costs 30–45% more per kg than equivalent polyester, and nylon-spandex fabrics dye at lower temperatures with acid dyes, increasing processing complexity. Polyester-spandex (80/20 to 88/12 poly-spandex) is the workhorse of mainstream athleisure — cooler to the touch, slightly crisper hand feel, excellent moisture-wicking when texturized, and significantly lower cost. Most sub-$40 retail athleisure uses polyester-spandex. For brands targeting volume price points, polyester-spandex in the 160–200 GSM range with microfiber polyester (50D/72F or finer) bridges the hand-feel gap substantially. **04. 4-Way Stretch for Movement: Denier and Content Optimisation** Getting 4-way stretch right in athleisure fabrics is a specification exercise, not a simple "add spandex" decision. Three variables interact: spandex denier, spandex content percentage, and covering yarn denier. Each controls a different aspect of the final stretch performance. Spandex denier (20D, 40D, 70D) controls the modulus — the force required to stretch the fabric. Lower denier spandex (20D) in leggings produces a softer, lower-compression feel suited to yoga and pilates. Higher denier (40D–70D) increases compression, appropriate for running tights and training leggings where muscle support is claimed. For mainstream athleisure (lifestyle wear, not sports-specific), 20D–40D spandex at 15–18% content in a 4-way stretch knit hits the sweet spot of movement freedom and shape retention. Spandex content percentage governs recovery force and sagging resistance. Below 12%, fabrics lack sufficient recovery for leggings; above 22%, they become uncomfortably compressive for casual wear. The 15–20% range delivers the right balance. Covering yarn denier affects weight and opacity as discussed above — the three variables must be specified together, not independently. --- ## Technical Specifications **Manufacturing specs for Spandex Athleisure.** **GSM Range** - Leggings / Yoga Pants: 160–220 GSM (lighter for summer/studio, heavier for year-round/cold-weather) - Sports Bras / Crop Tops: 140–180 GSM - Joggers / Track Pants: 220–280 GSM (often brushed or French terry constructions) - Typical sweet spot for multi-season athleisure leggings: 180–200 GSM in 4-way stretch interlock **Yarn Count** - Nylon covering yarn: 40D/34F to 70D/68F (finer filament counts = softer hand) - Polyester covering yarn: 50D/72F to 75D/72F (DTY textured for moisture management) - Spandex core: 20D (yoga/pilates), 40D (mainstream athleisure), 70D (compression/training) - Double-covered yarn preferred over single-covered for leggings — reduces bare spandex exposure at cut edges **Knit Construction** - **4-way stretch interlock**: Best for leggings and yoga pants — stitch structure provides equal stretch in warp and weft, recovers cleanly, produces flat back face suitable for printing - **Single jersey (1-way stretch)**: Suitable only for tops and casual pieces, insufficient for bottoms - **Circular knit rib (2x2 or 4x4)**: Ideal for waistbands and cuff applications within the garment - **Jacquard / mesh panels**: 20–30% of athleisure incorporates ventilation panels; spandex content can be reduced to 10–12% in mesh areas **Shrinkage** - 4-way stretch interlock (nylon-spandex): Length 2–4%, Width 1–3% after first wash at 30°C - Polyester-spandex: Similar, slightly less prone to length shrinkage - Heat-set finishing reduces shrinkage to under 2% in both dimensions — specify heat-setting in your tech pack **Pilling Resistance** - Nylon-spandex: Grade 4–5 (ISO 12945-2 Martindale, 5000 cycles) — nylon's high tenacity resists fibre breakage - Polyester-spandex: Grade 3–4 — microfiber polyester susceptible to pilling at abrasion points (inner thigh) - Specify anti-pilling finish or higher twist DTY polyester to improve grade **Colorfastness** - Wash fastness (ISO 105-C06): Grade 4–4.5 - Light fastness (ISO 105-B02): Grade 4–5 (UV stabilizers improve this to 5–6 for outdoor-use athleisure) - Rubbing fastness (ISO 105-X12): Dry Grade 4, Wet Grade 3–3.5 (common limitation — specify wet rubbing in QC) - Perspiration fastness (ISO 105-E04): Grade 4 — important for athleisure given intended use conditions **Tensile Strength** - Nylon-spandex fabric: 350–500 N (warp), 300–450 N (weft) — ASTM D5034 grab test - Polyester-spandex: 280–420 N — adequate for athleisure, not suitable for high-abrasion sportswear **MOQ Guidance** - Fabric (from mill): 500–1,000 metres per colourway per construction - Yarn (spandex, Invista/Hyosung brand): 100–200 kg minimum per denier/colour - Finished garments (CMT): 200–300 pieces per style per colourway at most Indian/Bangladesh factories - For nylon-spandex from Korean mills (top-tier quality): MOQs typically 1,500–3,000 metres --- ## Manufacturing & Sourcing Considerations **What to know before you source.** **Knitting Machine Requirements** Athleisure fabrics require circular knitting machines with spandex feed systems — not all knitting facilities have these. Positive feed mechanisms (MEMMINGER-IRO is the industry standard) maintain consistent spandex draw ratio across the fabric width, critical for uniform stretch performance. Machines without positive feed produce variable tension, leading to uneven opacity and patchy stretch recovery. For 4-way stretch interlock, specify that the mill uses machines with minimum 28-gauge needle beds — finer gauge produces tighter construction and better opacity. 24-gauge is acceptable for heavier jogger constructions but too open for leggings. **Dyeing Compatibility** Nylon-spandex: Requires acid dyeing at 85–95°C. Spandex tolerates this temperature range if process is controlled. Avoid exceeding 100°C — heat degradation begins and affects elastic recovery permanently. Polyester-spandex: Requires disperse dyeing at 130°C under pressure. Modern spandex (Lycra T-902C, ROICA SF series) is rated for this temperature, but lower-grade Chinese spandex degrades. Always verify spandex brand and heat rating before committing to polyester-spandex at high-temperature dye houses. Both constructions benefit from 2% owf (on weight of fabric) optical brightener in dyeing for white and light colourways, countering the slight yellow cast that spandex develops with heat exposure. **Finishing Processes** Heat-setting is mandatory for athleisure fabrics — it stabilises the knit structure, reduces shrinkage, and sets the final GSM. Specify heat-setting at 170–175°C for polyester-spandex, 150–155°C for nylon-spandex (nylon yellows above 160°C). Softener application (amino-silicone at 1.5–2% concentration) improves hand feel significantly in polyester-spandex, narrowing the hand-feel gap with nylon-spandex. Most Indian finishing houses apply silicone softeners as standard — confirm whether it's included in the price or specified separately. Bio-polishing (cellulase enzyme treatment) is not applicable to synthetic spandex blends — this is a cotton finishing process sometimes incorrectly specified. **Quality Control Checkpoints** - **Stretch and recovery test**: Fabric must recover to within 5% of original dimensions after 10 stretch-recovery cycles at 50% elongation — test in both warp and weft - **Opacity at stretch**: Test at 0% and 60% elongation; failures often appear only under stretch - **Seam strength**: Flatlock and overlock seams on spandex fabrics fail differently — specify seam test protocol - **Colorfastness to perspiration**: ISO 105-E04 — mandatory for athleisure given end use **Common Production Pitfalls** 1. **Spandex overfeed/underfeed variation** — visible as diagonal striping in the finished fabric; caused by inconsistent positive feed tension 2. **Dye temperature exceedance** — permanent stretch performance loss; non-detectable visually, only via lab testing 3. **Bare spandex at cut edges** — results in edge roll and customer returns; specify double-covered yarn and edge-sealed seams 4. **GSM creep** — mills sometimes deliver lighter GSM than specified to save yarn costs; weigh fabric on receipt and reject if more than 5% under specification **Lead Times** - Fabric from established Indian circular knit mills: 25–35 days - Fabric from Korean or Taiwanese mills (premium): 45–60 days + shipping - CMT garment production: 30–45 days after fabric approval - Full development cycle (fabric approval → bulk delivery): 90–120 days for new construction **Key Sourcing Regions** - India (Tirupur, Ludhiana): Strong circular knit capacity for polyester-spandex; nylon-spandex quality improving but still below Korean/Taiwanese standard - Korea/Taiwan: Premium nylon-spandex fabrics; significantly higher cost but brand-justified for $80+ retail price points - China (Fujian, Guangdong): High volume, competitive pricing; quality variance high — supplier audit essential --- ## Trade-Offs — Honest Assessment **Every fibre has limits. Here's the full picture.** **Strengths** - **Unmatched stretch-recovery performance**: No commercially available fiber at scale delivers 500–800% elongation with near-complete recovery. For leggings and yoga pants, spandex is non-negotiable — every alternative compromises on either stretch extent or recovery force. - **Dimensional stability across wear cycles**: A correctly engineered nylon-spandex or polyester-spandex fabric at 15–20% spandex content maintains shape through 80–100 wash cycles, directly reducing customer returns and brand damage from "stretched-out" garments. - **Compatible with performance finishes**: Moisture management, anti-odour (silver ion, copper-based), and UV protection finishes all apply cleanly to spandex blend fabrics — the polyurethane surface doesn't resist finish uptake the way hydrophobic synthetics can. - **Enabling complex garment construction**: Spandex's stretch tolerance simplifies pattern cutting (less precision required in sizing) and enables seamless construction — one continuous tube of fabric for leggings with no side seams, reducing production cost per unit. - **Opacity engineering control**: The interplay of spandex draw ratio, covering yarn denier, and stitch density gives designers and mills specific technical levers to engineer opacity — a brand can specify exactly the opacity performance they need and achieve it reliably. **Limitations** - **Non-biodegradable and difficult to recycle**: Spandex is polyurethane-based synthetic fiber. In blended fabrics, separating spandex from nylon or polyester for recycling is commercially unfeasible with current technology. Every spandex-blend garment that enters landfill will persist for hundreds of years. Recycled-content options (ROICA V550 claims 50% post-industrial recycled content, Lycra EcoMade uses 100% pre-consumer recycled polyurethane) exist but carry 25–40% price premiums and require supply chain verification. Brands with sustainability commitments must weigh this honestly. - **Heat and chemical sensitivity**: Spandex degrades irreversibly at temperatures above 150–160°C (depending on grade), and chlorine bleach destroys elastic performance within a few wash cycles. Care label communication must be explicit. Manufacturing processes — dye, heat-set, tumble dry — must all be controlled within these parameters, adding process complexity versus all-synthetic alternatives. - **Cost floor it sets on product pricing**: Spandex content at 15–20% adds meaningfully to fabric cost. At ₹800–1,200/kg for Invista or Hyosung branded spandex yarn, a 180 GSM fabric with 18% spandex content carries ₹25–40/metre in spandex yarn cost alone. This is manageable for mid-market and premium athleisure but makes sub-$15 retail price points structurally difficult in quality-compliant production. --- ## Cost Analysis **The economics of Spandex for Athleisure.** **Yarn Pricing (Indicative, India, 2024)** - Hyosung Creora standard spandex (20D): ₹850–1,050/kg - Hyosung Creora standard spandex (40D): ₹750–950/kg - Invista Lycra branded (20D): ₹1,100–1,400/kg (15–25% brand premium) - ROICA V550 (recycled, 20D): ₹1,300–1,600/kg - Chinese generic spandex (equivalent denier): ₹500–700/kg (quality variance significant) **Fabric Cost Impact** - 180 GSM nylon-spandex (80/20) circular knit: ₹450–600/metre (India mill gate) - 180 GSM polyester-spandex (88/12) circular knit: ₹280–380/metre (India mill gate) - Premium nylon-spandex from Korean mills: ₹700–950/metre CIF India **Cost-Per-Garment (Leggings, Indicative)** - Fabric consumption per pair of leggings: 1.2–1.4 metres (includes cutting waste) - Polyester-spandex fabric: ₹336–532/garment in fabric alone - Nylon-spandex fabric: ₹540–840/garment in fabric alone - CMT (cut-make-trim) addition: ₹150–300/garment at Indian factories - Total COGS before brand overheads: ₹500–800 (poly-spandex) to ₹700–1,150 (nylon-spandex) **Cost-Per-Wear Logic** A correctly engineered athleisure legging used 3x/week and lasting 18 months (approximately 234 wears before noticeable shape loss) at ₹700 COGS retails at ₹1,800–2,500 in India. Cost-per-wear at retail: ₹7.7–10.7. A lower-quality legging at ₹500 COGS that bags out in 60 wears retails at ₹999 — cost-per-wear ₹16.6. The premium fiber cost delivers actual value. **Comparison vs Alternatives** - Cotton/spandex (95/5) jersey: ₹220–300/metre — significantly cheaper, but inadequate stretch recovery for fitted leggings; suitable for casual t-shirt silhouettes only - PTT bicomponent stretch fabric: ₹350–500/metre — directional stretch only, insufficient for multi-directional athleisure - Spandex-blend fabrics remain the only cost-competitive path to performance athleisure at scale --- ## Sustainability Profile **Environmental and ethical considerations.** Conventional spandex is a petroleum-derived synthetic with a significant carbon footprint — Invista estimates 8–12 kg CO₂e per kg of Lycra produced. In a fabric that is 15–20% spandex, this contributes 1.2–2.4 kg CO₂e per kg of fabric, before considering the covering fiber's footprint. **Available Certifications** - OEKO-TEX Standard 100: Certifies absence of harmful substances (formaldehyde, heavy metals, pesticides) — available and meaningful; most reputable spandex suppliers carry this for their fabric customers - bluesign: Certifies responsible resource use in production — applicable to the full fabric, not yarn-stage for spandex - ROICA V550 Environmental Certification: Third-party verified recycled content (50% PIR) - Lycra EcoMade certification: 100% pre-consumer recycled polyurethane feedstock — Invista can provide chain of custody documentation **Biodegradability** Spandex is not biodegradable under any current commercial composting or anaerobic digestion standard. Blended spandex fabrics (nylon-spandex, polyester-spandex) cannot be mechanically or chemically recycled through existing textile recycling streams. This is the category's most significant unresolved environmental liability. **Consumer Perception** The athleisure consumer is increasingly scrutinising sustainability claims. Brands using recycled spandex (ROICA V550, Lycra EcoMade) can make credible marketing claims with certification documentation. Brands using conventional spandex face increasing pressure to disclose. The gap between "recycled polyester" messaging (widely adopted) and the silent use of virgin spandex in the same garment is a growing brand risk. --- ## FAQ **Spandex for Athleisure — answered.** **1. What makes spandex better or worse than elastane/Lycra alternatives for athleisure?** "Spandex" and "elastane" and "Lycra" are the same chemical — polyurethane fiber, called spandex in the US, elastane in Europe, with Lycra being Invista's brand name. The meaningful distinction is brand quality: Invista Lycra and Hyosung Creora are manufactured to tighter tolerances than generic Chinese spandex, producing more consistent draw ratio, better heat stability, and documented stretch recovery performance. For athleisure above the $30 retail price point, specifying Invista or Hyosung by name in your tech pack is worth the 20–30% cost premium — it's a quality assurance mechanism, not just marketing. **2. What's the minimum order quantity for spandex athleisure fabric?** Most Indian circular knit mills (Tirupur, Ludhiana) accept 500–1,000 metre MOQs per colourway for spandex blend fabrics. For a brand doing a 3-colourway legging launch at 300 units per colour, you're looking at roughly 400–450 metres per colourway — some mills will accommodate this if you're an established customer or using the same base construction across colours. Korean and Taiwanese mills typically require 1,500–3,000 metres per colour, making them practical only for brands with confirmed retail distribution or >2,000 unit runs. **3. How does spandex athleisure fabric perform after 50+ wash cycles?** Properly engineered polyester-spandex or nylon-spandex fabrics (Hyosung or Invista core yarn, heat-set finish, cold wash 30°C) retain 85–90% of original stretch recovery force after 50 wash cycles in controlled lab testing. The practical performance cliff comes from: hot washing (above 40°C degrades spandex measurably after 30 cycles), tumble drying on high heat (accelerates degradation significantly), and chlorine bleach contact (destroys elastic recovery within 5–10 washes). Cold wash, low heat dry, and no bleach care instructions maintain performance. Garments that "stretch out" after 10 washes are either using substandard spandex or the fabric was not heat-set correctly. **4. What GSM should I specify for athleisure leggings?** The standard range is 160–220 GSM depending on end use and season. 160–175 GSM produces a lightweight, summer-appropriate legging with good opacity in nylon-spandex; adequate for yoga studio use. 185–200 GSM is the all-season standard — heavier enough for year-round wear, still comfortable in warm environments. 200–220 GSM is appropriate for cold-weather tights or training leggings with a compression claim. Note that GSM alone doesn't determine opacity — construction and covering yarn denier matter equally. A 175 GSM nylon-spandex interlock will typically outperform a 190 GSM polyester-spandex jersey on opacity at stretch. **5. Is spandex suitable for printed athleisure fabrics?** Yes — 4-way stretch spandex blend fabrics print well via sublimation (polyester-spandex, minimum 85% polyester required for sublimation transfer) and via rotary/flatbed screen printing. Sublimation on polyester-spandex is the dominant method for all-over print athleisure — prints are embedded in the fiber, not on the surface, so they stretch with the fabric without cracking. Nylon-spandex does not sublimation print (nylon lacks the affinity for disperse dyes used in sublimation) and requires screen printing or digital pigment print — these sit on the fabric surface and may crack on high-stretch areas. Match your print method to your fiber choice when specifying athleisure. **6. What certifications should I look for when sourcing spandex athleisure fabric?** For the fabric: OEKO-TEX Standard 100 (Class I for skin-contact garments) certifies absence of harmful chemicals — this is the baseline requirement. For manufacturing: bluesign or GRS (Global Recycled Standard) for brands with sustainability positioning. For yarn: request Invista's Lycra certification cards or Hyosung's Creora documentation — these confirm you're receiving genuine branded fiber, not generic substitutes relabelled. For India-based mills: WRAP (Worldwide Responsible Accredited Production) or SA8000 for social compliance. GOTS certification is not applicable to synthetic spandex blends. **7. How does spandex handle waistband engineering in athleisure?** Athleisure waistbands require a different spandex specification than the body fabric. A wide waistband (7–10 cm) in a legging needs higher spandex content (20–25%) and heavier spandex denier (40D–70D) to provide the "stay-up" compression force that prevents waistband roll-down during activity. Many brands use a separate waistband fabric (different GSM, higher spandex content) sewn onto the body panel. Alternatively, yarn-dyed jacquard waistbands with integrated spandex channel for an elastic insert provide a more secure hold. The critical failure mode to engineer against: waistband delamination at the attachment seam — specify flatlock stitching with 4-thread overlock finishing at the attachment points. **8. What's the typical lead time for spandex athleisure orders?** For established styles in production at an existing mill relationship: fabric 25–35 days, CMT 30–45 days after fabric approval — total 55–80 days from order to delivery. For new fabric construction development (new GSM, new construction, new colour): add 30–45 days for sample development and approval, bringing development cycle to 90–120 days. Korean/Taiwanese mill orders add 15–20 days shipping time. Plan seasonal athleisure collections on 16–20 week development cycles from design brief to bulk delivery to allow for lab testing, approval rounds, and shipping buffer. --- ## Related Links **Related Applications for Spandex** - [Activewear](/yarn/spandex/activewear) - [Sportswear](/yarn/spandex/sportswear) - [Loungewear](/yarn/spandex/loungewear) - [Underwear & Basics](/yarn/spandex/underwear-basics) **Alternative Fibers for Athleisure** - [Polyester for Athleisure](/yarn/polyester/athleisure) - [Modal for Athleisure](/yarn/modal/athleisure) - [Merino Wool for Athleisure](/yarn/merino-wool/athleisure) - [Nylon for Athleisure](/yarn/nylon/athleisure) - [Tri-Blend for Athleisure](/yarn/tri-blend/athleisure) **Glossary Terms** - [Denier](/glossary/denier) - [Fabric Weight (GSM)](/glossary/fabric-weight) - [Colorfastness](/glossary/colorfastness)