What Is Modal Jersey Fabric? Properties, GSM, and Care
Modal jersey is a single-knit fabric made from modal fiber — a regenerated cellulose (rayon) produced by chemically dissolving and re-spinning beech-wood pulp — knitted in a jersey weft-knit structure. Most retail modal jersey weighs 130–260 GSM, includes 4–7% spandex for stretch, and is used for T-shirts, pajamas, underwear, bralettes, and loungewear because of modal fiber’s fine ~1 dtex linear density and ~11–13% moisture regain at 65% RH, 20 °C (vs cotton’s 1.5–2.5 dtex and 7–8% regain). Under ISO 2076:2021, modal is a man-made cellulosic fiber; under FTC 16 CFR 303 (Textile Fiber Products Identification Act), it must be disclosed as “rayon” or “modal,” not “natural.”
Most consumer-facing descriptions conflate two distinct concepts — modal (the fiber) and jersey (the knit structure) — and use adjectives like “luxurious,” “silky,” or “premium” without measurable backing.
What modal jersey fabric actually is — fiber and knit, separately
The phrase “modal jersey fabric” is a compound of two independent textile concepts:
- Modal is a fiber — specifically, a high wet modulus (HWM) regenerated cellulose fiber. Modal can also be woven (modal poplin, modal twill) or knit in structures other than jersey (rib, interlock).
- Jersey is a knit structure — specifically, a single weft knit with a smooth face and looped reverse. Jersey can be made from cotton, polyester, viscose, lyocell, wool, or any combination thereof.
Modal jersey is the intersection: modal fiber yarn knitted in a single jersey weft-knit construction. Same fiber-vs-construction two-axis logic explains why poplin and oxford behave differently in identical fibers — see the shirt fabric types overview.
Common modal jersey compositions on the U.S. retail market
Across U.S. specialty fabric retailers (Mood Fabrics, Discovery Fabrics, Morex Fabrics, Nature’s Fabrics, Sitka Fabrics, California Textile Group), the dominant blends are:
| Composition | Typical use case |
|---|---|
| 100% modal | Lingerie, sleepwear, basic tees with limited stretch |
| 95% modal / 5% spandex (elastane) | Premium underwear, fitted tees, leggings |
| 93% modal / 7% spandex | Athletic-leaning loungewear, base layers, fitted dresses |
| 96% modal / 4% spandex (Siro yarn-spinning) | Mid-weight T-shirts, sleepwear |
| 50–60% cotton / 35–40% modal / 5% spandex | Casual T-shirts, tri-blend-style tees |
| 50% modal / 50% polyester | Activewear-leaning stretch jersey |
The spandex percentage and any cotton or polyester content alter performance more than the modal percentage alone. The 4–7% spandex range is most common; some lightweight lingerie modal jersey uses up to 10%.
The 50/50 modal/polyester blend exists because polyester is ~4–5× cheaper as a raw material than modal — dimensional stability and wrinkle resistance are side effects of cost-driven blending, not the primary motivation. The consumer trade-off: regain drops from modal’s ~11–13% toward polyester’s ~0.4%, plus microplastic shedding every wash. For 8h+ skin-contact garments (T-shirts, sleepwear, underwear), modal/polyester blends are mentioned informationally only; 100% modal, modal/spandex, or cotton/modal blends are the naturals-first options in the same use cases.
How modal jersey fabric is made
Two stages: making the modal fiber, then knitting it into a jersey fabric.
Modal fiber production — modified viscose / HWM rayon
The starting material is beech-wood pulp (primarily Fagus sylvatica), chosen for its short, uniform cellulose chains. Lenzing AG sources beech wood from FSC- or PEFC-certified European forests for branded TENCEL™ Modal.
The fiber-spinning process is a modified viscose process. Pulp is treated with sodium hydroxide (NaOH) to produce alkali cellulose, then exposed to carbon disulfide (CS₂) to form sodium cellulose xanthate. The xanthate is dissolved in dilute NaOH to produce a viscous liquid, extruded through spinnerets into a coagulating bath of dilute sulfuric acid, which regenerates the cellulose into solid fiber.
Two process modifications distinguish modal from standard viscose:
- A different ratio of cellulose, alkali, and carbon disulfide produces yarn with higher cellulose polymerization and crystallinity.
- Stretching during the spinning bath increases molecular orientation along the fiber axis.
The result is high wet modulus (HWM) rayon — retaining ~50–70% of dry strength when wet vs ~35–45% for standard viscose (per Textile Exchange glossary and Lenzing data). HWM grade is what makes modal practical for repeated laundering at retail price points.
From fiber to fabric — single jersey weft knit
Modal fiber is spun into yarn (commonly Ne 30s–60s for jersey) and fed into circular knitting machines. The dominant construction is the single jersey weft knit (plain jersey) — smooth face, looped reverse. Same structure as most cotton T-shirt jersey.
Less common constructions:
- Rib knit (1×1 or 2×2): alternating knit-and-purl wales; used for cuffs, necklines, form-fitting tops.
- Interlock: two interlocked single jerseys, double-thickness, smoother on both sides; used for higher-weight loungewear.
- French terry: looped reverse, smoother face, thickened back; uncommon in 100% modal, seen in cotton/modal blends.
Where modal/spandex jersey is specified, the spandex is plated or core-spun with the modal yarn during knitting, providing four-way stretch beyond what the loop structure delivers. Plain 100% modal jersey has mechanical stretch only — 20–40% in the course direction — which is why retail modal jersey is overwhelmingly modal/spandex.
Modal jersey fabric properties — measurable values
Modal jersey at a glance
| Property | Typical value | Source / reference |
|---|---|---|
| Fiber type | Regenerated cellulose (HWM rayon) | ISO 2076:2021; FTC 16 CFR 303; Textile Exchange glossary |
| Raw material | Beech wood pulp (primarily Fagus sylvatica) | Lenzing AG technical data |
| Fiber linear density (standard modal) | ~1 dtex | Industry data; Morton & Hearle, Physical Properties of Textile Fibres, 4th ed. (Woodhead, 2008) |
| Fiber linear density (micro modal) | ~1.0 dtex (<1 denier, ≈0.9 denier per Lenzing) | Comparative micro-modal/standard-modal lingerie fabric study, PMC12074228; Lenzing TENCEL™ Micro technology |
| Cross-section shape | Near-round, regular | Same comparative study |
| Moisture regain | ~11–13% at 65% RH, 20 °C | Standard textile-fiber tables (rayon/HWM regain range); ISO 6741-1 mass-determination methodology |
| Wet strength (HWM grade) | ~50–70% of dry strength | Textile Exchange glossary; Lenzing technical data |
| Knit structure (most common) | Single jersey weft knit | Industry standard for retail modal jersey |
| Typical GSM range | 130–260 g/m² | Synthesized from Mood Fabrics, Discovery Fabrics, Morex Fabrics, Nature’s Fabrics, Sitka Fabrics retail specs |
| Typical width | 58–62” (147–158 cm) | Same retailer panel |
| Common blends | 100% modal; 95/5 modal/spandex; 93/7 modal/spandex; 50/35/5 cotton/modal/spandex | Same retailer panel |
| Stretch (modal/spandex) | ~70%+ horizontal, ~50%+ vertical, four-way | Discovery Fabrics, Morex Fabrics product specifications |
| Stretch (100% modal) | 20–40%, primarily horizontal (mechanical from knit) | Retailer notes; Dharma Trading product description |
Comparison: modal jersey vs cotton, micro modal, and viscose jersey
Like-for-like single jersey weft knit, retail-grade fabric, 5% spandex where indicated:
| Property | Modal jersey | Cotton jersey | Micro modal jersey | Viscose (standard rayon) jersey |
|---|---|---|---|---|
| Fiber linear density | ~1 dtex | 1.5–2.5 dtex | ~1.0 dtex (<1 denier) | 1.5–2 dtex |
| Moisture regain (65% RH, 20 °C) | ~11–13% | ~7–8% | ~11–13% | ~12–14% |
| Wet strength as % of dry | ~50–70% (HWM) | ~110% (cotton gains strength wet) | ~50–70% | ~35–45% (standard viscose) |
| Typical jersey GSM range | 130–260 | 130–260 | 130–230 | 110–220 |
| Typical stretch with 5% spandex | 70%+ both directions | 50–70% both directions | 70%+ both directions | 40–60% both directions |
| Pilling resistance | Good (smooth filament) | Variable (depends on staple length and finish) | Slightly lower than standard modal per published comparison | Lower than modal |
| Shrinkage on first wash (pre-shrunk) | <5% | 5–10% | <5% | 5–10% |
| Drape | Fluid | Crisper | Very fluid | Very fluid (but weaker wet) |
Sources: PMC12074228; Textile Exchange glossary; Lenzing AG technical data. See also the cotton vs polyester breathability data for cotton and synthetic baselines.
Modal jersey GSM by application
Fabric weight is the most decisive variable in modal jersey wear performance — more than fiber identity within the modal/cotton/viscose band. U.S. specialty fabric retailer specs group as follows:
| GSM range | Weight class | Typical applications | Example product (sourced from SERP) |
|---|---|---|---|
| 130–170 | Lightweight | Lingerie, tank tops, lightweight tees, summer dresses, sheer-leaning lining | Nature’s Fabrics ~165 GSM modal/spandex jersey |
| 170–220 | Mid-weight | T-shirts, basic loungewear, leggings, pajama tops | Morex Fabrics 200 GSM 96/4 modal/spandex; Sitka 200 GSM cotton/modal/spandex |
| 220–260 | Heavyweight | Premium loungewear, fitted dresses, structured tops, fitted bottom layers | Discovery Fabrics 215 GSM micro modal jersey; 240 GSM 4-way stretch from major marketplace listings |
Below ~150 GSM in lighter colors, modal jersey can become semi-transparent — a recurring complaint in consumer reviews of inexpensive modal T-shirts. Above 260 GSM, modal jersey loses much of the fluidity that distinguishes it from cotton jersey at equivalent weight.
Modal jersey vs cotton jersey
Knit-jersey-specific differences (for fiber-level comparison: ). At equivalent single jersey weft-knit construction and GSM:
- Drape and hand: modal jersey drapes more fluidly at equivalent GSM. The smoother near-round fiber cross-section produces lower yarn surface friction, so the knit loops settle into a more fluid hand than cotton jersey at the same fabric weight.
- Shrinkage (AATCC 135): quality pre-shrunk modal jersey typically shrinks under 5% in length and width on first wash; cotton jersey of comparable weight typically shrinks 5–10%. Cotton/modal blends fall between the two.
- Pilling: modal’s smoother filament surface generally pills less than cotton in like-for-like jersey, though weft-knit jersey of any fiber pills more readily than corresponding woven fabric.
- Wet-wash tolerance: cotton jersey gains roughly 10% strength wet; HWM modal retains ~50–70% of dry strength wet — so cotton jersey tolerates higher wash temperatures and harsher agitation than modal of equivalent grade. The fiber-level mechanism is covered in the viscose shrinkage and wet-strength data for regenerated cellulose fibers.
- Cost: modal jersey at retail is typically priced 50–150% above comparable cotton jersey in the U.S. specialty fabric market.
Modal jersey vs micro modal jersey
“Micro modal” is modal fiber spun in the microfiber range — under 1 denier per filament (≈0.9 denier per Lenzing’s TENCEL™ Micro technology specification, ~1.0 dtex per the Tomljenović & Živičnjak 2025 lingerie-fabric study) vs standard modal’s ~1–1.3 dtex. The most commonly cited certified product is TENCEL™ Modal Micro (Lenzing AG). At equivalent jersey construction, micro modal produces a softer, smoother hand and finer surface luster, with lower wear resistance and higher cost (PMC12074228).
Deep-dive on micro modal in underwear (microbial behavior, skin pH, FTC labeling): .
What modal jersey is used for
Across U.S. specialty fabric retailers and finished-garment categories, the dominant applications of modal jersey are:
- T-shirts and basic tops — typically 170–220 GSM with 4–7% spandex.
- Pajamas and sleepwear — 130–200 GSM, often with cotton blended in.
- Underwear and bralettes — 130–180 GSM micro modal or modal/spandex; the smooth fiber surface and high regain are positioned as next-to-skin advantages.
- Tank tops and camisoles — 130–170 GSM.
- Loungewear and joggers — 200–260 GSM, frequently in cotton/modal/spandex tri-blend.
- Dresses and fitted casualwear — 180–240 GSM, often modal/spandex.
- Athletic base layers — 160–220 GSM modal/spandex or modal/polyester.
- Bed sheets — less common than woven modal sheets, found at the lower end of the bedding market. The fiber-vs-construction distinction in the bamboo vs percale weave-vs-fiber breakdown applies the same way to modal sheets.
Is modal jersey breathable? Fiber regain vs fabric air permeability
Most consumer-facing claims that “modal is more breathable than cotton” conflate two distinct properties:
- Moisture regain — fiber property, water uptake at equilibrium. Modal ~11–13%, cotton ~7–8%.
- Air permeability — fabric property, measured under ASTM D737 / ISO 9237 in cc/s/cm². Depends on knit density, GSM, and stitch geometry, not fiber identity.
A 250 GSM modal jersey can have lower air permeability than a 150 GSM cotton jersey, despite modal’s higher regain. Fabric weight dominates fiber effect within the modal/cotton/viscose band. See the air permeability data showing 14% advantage for cotton over polyester at equivalent construction.
For hot-weather modal jersey:
- GSM and knit openness drive heat retention more than fiber.
- Lightweight modal/spandex at 130–170 GSM allows substantial air movement.
- Heavyweight modal jersey at 220+ GSM is dense and warm regardless of regain.
- Sweat management (one-way wicking, drying speed) is measured under AATCC 195 — a separate property from regain or air permeability.
Is modal jersey sustainable? TENCEL™ Modal vs generic modal
The “modal” label alone does not indicate environmental controls — sustainability depends on the fiber producer, not the knit construction. TENCEL™ Modal (Lenzing AG) uses FSC- or PEFC-certified beech wood, recovers ~95% of process chemicals in a closed-loop system, and carries TÜV Austria certification for biodegradability in soil, freshwater, and marine environments. Generic modal without comparable controls can have substantially higher chemical waste and unverified wood sourcing. Carbon disulfide (CS₂) emissions in the viscose process are controlled at the production-facility level, not by fiber name.
Verify sustainability claims via certifications (TENCEL™, OEKO-TEX®, FSC/PEFC), not the word “modal” on a label. Full deep-dive on Lenzing’s process and life-cycle figures: . See the methodology page for site standards.
How to wash modal jersey
Care guidance from Lenzing, Discovery Fabrics, Morex Fabrics, and Dharma Trading converges on:
- Water temperature: cool or warm, under 30 °C (86 °F); some retailer instructions allow up to 40 °C (104 °F).
- Detergent: mild, pH-neutral. Enzyme detergents acceptable; avoid heavy alkaline detergents and chlorine bleach.
- Bleach: no chlorine bleach. Oxygen-based bleach (sodium percarbonate) at low concentration is acceptable for whites.
- Wash action: delicate or normal cycle. Avoid prolonged high-spin agitation (modal stretches and pills at the wet stage).
- Drying: low or no dryer heat. Lay flat or hang dry.
- Ironing: low-to-medium heat (under 150 °C / 300 °F). Low-setting steam if needed.
Modal at HWM grade retains ~50–70% of dry strength when wet — better than standard viscose (~35–45%) but lower than cotton (which gains ~10% wet). High temperatures accelerate pilling, surface fuzz, and dimensional change.
Some retailer content claims modal can be machine-washed at 60 °C (140 °F) like cotton — this does not align with Lenzing’s own care guidance or most published instructions.
Common claims about modal jersey, reviewed against published data
”Modal is a type of nylon”
Inaccurate. Nylon is a synthetic polyamide derived from petroleum (nylon 6, nylon 6,6). Modal is a regenerated cellulose fiber from wood pulp via the modified viscose process. Under ISO 2076:2021, modal is a man-made cellulosic; under FTC 16 CFR 303, modal must be labeled “modal” or “rayon,” nylon as “nylon” or “polyamide.” The claim appears on at least one prominent U.S. retailer product page for modal jersey — it is a factual error.
”Modal absorbs 50% more moisture than cotton”
Approximately consistent with regain data — modal ~11–13% vs cotton ~7–8% is roughly a 50% relative difference. The number conflates two concepts:
- Absorption capacity (equilibrium moisture in the fiber) — modal exceeds cotton.
- Moisture management (wicking, drying speed, evaporative resistance) — measured under AATCC 195 and ISO 11092 (RET), not by regain. Most modal jersey at retail does not publish AATCC 195 data.
The 50% regain ratio is technically correct but does not necessarily translate to a 50% advantage in sweat management.
”Modal jersey is hypoallergenic”
Not enforceable. “Hypoallergenic” has no regulatory definition for textiles in the U.S. The FDA has stated the term has no regulatory meaning even for cosmetics; for textiles, no comparable enforcement standard exists. Modal’s smooth near-round cross-section reduces mechanical friction vs cotton’s irregular cross-section, which can lower mechanical irritation — but allergic contact dermatitis from residual dyes, formaldehyde-releasing finishes, or processing chemicals is possible regardless of fiber. OEKO-TEX® Standard 100 tests for harmful chemical residues but does not certify “hypoallergenic” status.
”Modal is a natural fiber”
Inaccurate. Modal is a man-made cellulosic (regenerated cellulose) under ISO 2076:2021. The raw material is plant-derived, but the fiber is the product of chemical dissolution and re-extrusion. Under FTC 16 CFR 303, modal must be disclosed as a separate generic fiber category, not as a natural fiber.
”Modal has natural antibacterial properties”
Not certified. Modal has no inherent antibacterial properties beyond what clean cellulosic fibers offer. The FTC has issued enforcement actions against bamboo viscose retailers for similar antibacterial claims (where the source plant’s antibacterial properties do not survive the viscose process). Verified antibacterial behavior requires applied antimicrobial finishes tested under AATCC 100 or ISO 20743.
”Modal feels like silk”
Partially accurate as a comparative descriptor only. Modal’s smooth near-round cross-section produces a luster and hand-feel comparable to silk in qualitative terms, but the chemistry is unrelated — silk is a protein fiber (fibroin) from Bombyx mori silkworms, modal is regenerated cellulose.
Modal jersey in the regenerated cellulose family
Modal sits within a larger family of man-made cellulosic fibers, each produced by a different chemical route from similar wood-pulp starting materials:
| Fiber | Process | Typical wet strength | Notable trade name |
|---|---|---|---|
| Standard viscose / rayon | NaOH + CS₂, dilute H₂SO₄ regeneration | ~35–45% of dry | (generic; LENZING™ ECOVERO™ for branded sustainable viscose) |
| Modal (HWM rayon) | Modified viscose with stretching during spinning | ~50–70% of dry | TENCEL™ Modal (Lenzing) |
| Lyocell | NMMO solvent, closed-loop, no CS₂ | ~70–80% of dry | TENCEL™ Lyocell (Lenzing) |
| Cupro | Cuprammonium solvent (copper + NH₃) | ~40–50% of dry | (small commercial volume; Bemberg by Asahi Kasei) |
| Acetate / Triacetate | Acetic anhydride esterification of cellulose | ~30–40% of dry | (filament for linings, formal wear) |
TENCEL™ Lyocell is modal’s closest commercial relative — it uses NMMO (N-methylmorpholine N-oxide) instead of NaOH and CS₂, eliminating carbon disulfide and operating in a more closed-loop system with higher solvent recovery. Lyocell commands a price premium over modal and is more common in woven than knit applications.
Sources
Standards:
- ISO 2076:2021 — Textiles — Man-made fibres — Generic names. Classifies modal as a man-made cellulosic fiber. iso.org/standard/79685
- ISO 6741-1:1989 — Textiles — Fibres and yarns — Determination of commercial mass of consignments — Part 1: Mass determination and calculations. Methodology behind moisture regain reporting. iso.org/standard/13199
- ISO 9237:1995 — Textiles — Determination of the permeability of fabrics to air. iso.org/standard/16869
- ISO 11092:2014 — Textiles — Physiological effects — Measurement of thermal and water-vapour resistance under steady-state conditions (sweating guarded-hotplate test, RET). iso.org/standard/65962
- ASTM D737-18 — Standard Test Method for Air Permeability of Textile Fabrics. astm.org/d0737-18r23
- ASTM D3776/D3776M-20 — Standard Test Methods for Mass Per Unit Area (Weight) of Fabric. astm.org/d3776_d3776m-20
- ASTM E96/E96M-24a — Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials. astm.org/e0096_e0096m-24a
- AATCC TM 100 — Antibacterial Finishes on Textile Materials: Assessment of. aatcc.org
- AATCC TM 135 — Dimensional Changes of Fabrics after Home Laundering. aatcc.org
- AATCC TM 195 — Liquid Moisture Management Properties of Textile Fabrics. aatcc.org
- FTC Textile Fiber Products Identification Act, 16 CFR Part 303 — Fiber-content disclosure rules; basis of modal/rayon labeling requirements and bamboo-as-rayon enforcement actions. ecfr.gov/title-16/part-303
Peer-reviewed studies:
- Tomljenović, A. & Živičnjak, J. (2025) — Comparative Property Analysis of One-by-One Rib Lingerie Fabrics Fabricated from Modal Fibers and Microfibers, Nanomaterials 15(9):653. Standard modal (1.3 dtex) vs modal microfiber (1.0 dtex) fabric performance differences. pmc.ncbi.nlm.nih.gov/articles/PMC12074228
Reference books:
- Morton, W.E. & Hearle, J.W.S. (2008) — Physical Properties of Textile Fibres, 4th ed., Woodhead Publishing, Cambridge. Reference values for fiber linear density, moisture regain, tenacity, and wet strength.
Brands and certifications:
- Lenzing AG (Austria) — TENCEL™ Modal product technical data and sustainability reports; closed-loop process, ~95% solvent recovery, FSC/PEFC certification, TÜV Austria biodegradability certification. lenzing.com
- Textile Exchange — “Modal” glossary entry; HWM rayon classification, history (commercial introduction of modal in 1951 in Japan; Lenzing scaling in 1964), basic technical definition. textileexchange.org
- OEKO-TEX® Standard 100 — Tested for harmful substances; chemical-residue testing standard for direct-skin-contact apparel. oeko-tex.com
- FSC (Forest Stewardship Council) — Wood-sourcing certification used by Lenzing for beech-wood pulp. fsc.org
- PEFC (Programme for the Endorsement of Forest Certification) — Wood-sourcing certification used by Lenzing for beech-wood pulp. pefc.org
- TÜV Austria — Certification body for biodegradability claims (soil, freshwater, marine environments) cited by Lenzing for TENCEL™ Modal. tuv.at
- FTC (U.S. Federal Trade Commission) — Enforcement authority for fiber-content disclosure and bamboo-as-rayon actions. ftc.gov