French Terry & Sweatshirt Fabric: How to Choose GSM, Fiber Content, and the Right Weight for Every Garment
French terry is the workhorse knit fabric for everyday basics. Hoodies, sweatshirts, joggers, track suits, cardigans, dresses, loungewear, and children's clothing are all built on this fabric. But the right GSM, fiber content, and backing finish varies significantly depending on what you're making. This guide walks you through how to read a supplier spec sheet and choose the correct fabric for your project — not just the closest option available.
What You Can Make from French Terry and Sweatshirt Fleece
This fabric family covers a wide range of end uses. The two key variables when matching fabric to garment are GSM and whether the back is brushed or loop-back.
Hoodies and sweatshirts. The most common application by far. For transitional-season styles, use 240–280 GSM loop-back (unbrushed). For autumn and winter, use 280–340 GSM brushed fleece. For lightweight summer hoodies, 180–220 GSM two-thread french terry (loop-back) is ideal. The season drives the weight.
Joggers and sweatpants. For winter, use heavyweight french terry (loop-back) or brushed fleece at 280–320 GSM. For warmer weather, 240–280 GSM unbrushed is the right call. Add 3–5% spandex (elastane) for slim or tapered cuts; relaxed-fit joggers generally don't need it.
Track suits. A hoodie and matching bottoms cut from the same fabric. For winter: brushed fleece at 300–320 GSM. For spring and autumn: 240–280 GSM loop-back. Fabric consumption for one adult suit runs 2.2–2.8 m (approximately 2.4–3.1 yd) when cut individually, and 1.9–2.3 m (2.1–2.5 yd) in a production run.
Cardigans and zip-throughs. Winter-weight styles call for 320–400 GSM, brushed or loop-back. Open-front cardigans without a hood are often cut from dense 350–400 GSM loop-back fleece for a cleaner drape and sharper silhouette.
Sweater dresses and longline tunics. Use 280–320 GSM brushed or loop-back fleece. Loop-back gives a more structured, polished look; brushed fleece reads warmer and more casual. Premium sweater dresses often use 320–400 GSM loop-back for a substantial hand and clean seams.
Loungewear and pyjamas. Lightweight two-thread french terry at 180–220 GSM works well for summer lounge sets. For winter loungewear, use brushed fleece at 280–320 GSM. For pyjamas, stick to 100% cotton for skin comfort and hypoallergenic properties.
Long-sleeve tops and base layers. Not the primary end use, but two-thread french terry at 180–200 GSM and interlock knit at 200–240 GSM are both good choices for transitional-season long-sleeved tops, turtlenecks, and lightweight pullovers. Interlock is particularly well suited here because both faces are identical, which gives a clean finish at a mock neck or crew collar.
Children's clothing. Softness and hypoallergenic properties come first. Use 180–220 GSM two-thread french terry or 200–220 GSM interlock knit, both in 100% cotton. For winter children's suits, move to 280–300 GSM brushed fleece in 100% cotton.
Corporate merch and print-ready blanks. Hoodies, sweatshirts, and pullovers destined for screen printing or embroidery. Target 280–320 GSM in an 80/20 or 65/35 cotton/polyester blend for durability under repeated decoration. Loop-back (unbrushed) is preferable for print work — the pile on brushed fleece interferes with sharp ink transfer.
Two-Thread vs. Three-Thread French Terry
This is the primary decision point when buying sweatshirt fabric. It determines thickness, warmth, and seasonality.
Two-thread french terry (loop-back) is constructed from two yarn systems. The face is smooth; the back has a characteristic small loop texture. GSM typically runs 180–230. It's lightweight, breathable, and well suited to spring and summer hoodies, lightweight loungewear, long-sleeve tops, and children's styles. It provides little insulation on its own, so it's only appropriate as a winter layer when worn under outerwear.
Three-thread french terry (heavyweight french terry / sweatshirt fleece) adds a third yarn that lies against the back of the fabric, adding bulk, weight, and warmth. GSM ranges from 240 to 460 depending on construction. This is the standard fabric for autumn/winter hoodies, sweatpants, track suits, and cardigans. It comes in two back finishes — loop-back (unbrushed) and brushed fleece — and that distinction matters. The brushed version traps warmth much like a thin fleece; the loop-back version keeps a clean, smooth inside. Heavy loop-back options at 350–400 GSM offer warmth comparable to brushed fleece while providing a cleaner surface for print work and a neater seam finish.
For a standard everyday hoodie or track suit, three-thread french terry at 280–320 GSM is the production standard across the industry.
Comparing Two-Thread French Terry, Three-Thread French Terry, and Interlock
A quick reference to help you choose the right fabric type without getting lost in technical detail.
Parameter
Two-Thread French Terry
Three-Thread Loop-Back (Unbrushed)
Three-Thread Brushed Fleece
Interlock Knit
GSM
180–230
240–400
280–460
200–240
Back Finish
small loops
loops (fine to dense)
brushed pile
smooth both sides
Warmth
low
medium to high
high
medium
Season
summer, transitional
year-round depending on GSM
autumn–winter
year-round
Print Suitability
yes
yes
poor (pile surface)
yes
Typical Wholesale Price
budget–mid
mid
mid–premium
mid
The GSM range of three-thread loop-back is broader than most buyers expect. At 240–280 GSM it's a transitional-season fabric; at 300–340 GSM it becomes a viable winter option with a dense, tight loop; at 370–400 GSM it's a heavy winter fleece fabric without any brushed pile; and at 410–460 GSM it's typically bonded with a Euro plush backing, functioning more like an insulated shell than a standard sweatshirt knit.
Choosing GSM by Season and Garment Type
GSM — grams per square meter — is the single most important number on a fabric spec sheet. It tells you what season the fabric belongs to and which garments it supports.
180–220 GSM. Two-thread french terry (loop-back). Use for summer hoodies, lightweight loungewear sets, children's summer styles, long-sleeve base layers, and lightweight pullovers worn under a jacket. Warmth comes from garment construction (a hood, a lining) rather than the fabric itself.
200–240 GSM. 100% cotton interlock knit. A true year-round fabric. Works for long-sleeve tops, turtlenecks, simple office-appropriate knit dresses, and children's underlayers. The identical two-faced structure finishes cleanly at mock necks and cuffs.
240–280 GSM. Three-thread loop-back fleece or lightly brushed two-thread french terry. The transitional-season standard. Use for spring and autumn hoodies, sweatshirts, and lightweight track suits. Comfortable at 50–60°F (10–15°C) without overheating.
280–320 GSM. Three-thread brushed fleece or dense three-thread loop-back. The mainstream production standard. This is the go-to weight for everyday autumn/winter hoodies and track suits, base-layer-friendly styles worn under outerwear, branded merch, and corporate uniform programmes.
320–400 GSM. Dense brushed fleece or heavy loop-back. Use for winter hoodies, cold-weather loungewear, insulated pullovers, and cooler-weather sweatpants. Loop-back at 350–400 GSM is the right call when maximum weight is needed alongside clean print or embroidery results — the pile on brushed fleece compromises fine detail in artwork.
410–460 GSM. Three-thread french terry bonded with Euro plush backing. At this weight it is no longer a standard sweatshirt fabric — it functions as an insulated outer-layer fabric for winter parkas, extreme-cold pullovers, and workwear outershells. Rarely used for basic hoodies or sweatpants; more common in outerwear and technical garment construction.
Fiber Content: What to Look for
Fiber content determines how the finished garment behaves after 10–15 washes. Here is what matters.
Cotton, 65–100%. The primary fiber. Higher cotton content means softer hand-feel and better skin comfort, but the fabric is more prone to bagging at the knees and cuffs over time. 100% cotton is the right choice for premium garments, children's clothing, and pyjamas where hypoallergenic properties and tactile quality are priorities.
Polyester, 15–35%. The shape-retention additive. Garments in a 65/35 or 80/20 cotton/polyester blend hold their form after 20 or more washes in the same way they did when new. Blended fabrics dominate the mass-market and branded merch space for exactly this reason — the finished product stays presentable for longer.
Spandex (elastane), 3–5%. An optional addition for fitted cuts: tapered sweatpants, leggings, fitted sports tops, and body-con sweater dresses. A classic relaxed-fit hoodie or straight-leg jogger does not need it.
What to avoid: rayon (viscose) above 10% in the fiber blend, and any listing marked simply "synthetic" without a percentage breakdown. Rayon stretches out after washing and loses its appearance within a single season.
Yarn Spinning Technology: Open-End, Carded, Combed, and Compact Combed Cotton
Beyond fiber content and GSM, the yarn spinning method has a significant impact on the quality of the finished garment. There are four main tiers in the market, running from entry-level to premium. The spinning method is usually noted on the supplier spec sheet alongside the fabric construction — for example, "loop-back, carded" or "loop-back, compact combed."
Open-end cotton (OE / rotor-spun). The most affordable spinning technology, characterized by a broken fiber end. The yarn is dense but rougher to the touch and tends to pill after 10–15 washes. Suitable for high-volume promotional merch, corporate giveaway runs, and everyday workwear where price is the primary driver rather than tactile quality. Typically the lowest price tier at wholesale.
Carded cotton. Cotton yarn spun from medium-length fibers after carding. The mass-market standard. The fabric is even and holds its shape well, though it feels slightly stiffer than combed cotton on first touch. It softens noticeably after two or three washes. The vast majority of mainstream retail and e-commerce sweatshirt fabric is carded. Mid-tier wholesale pricing.
Combed cotton (pенье). Yarn spun from long-staple cotton that has been combed to remove short fibers and align the remaining ones. The yarn is smooth, strong, and has a slight sheen. Fabric made from combed cotton feels noticeably better against the skin than carded, holds color longer, and stays presentable for more seasons. The right choice for premium basics, quality branded merchandise, and children's clothing. Higher wholesale price point.
Compact combed cotton. An enhanced version of combed cotton where air is removed from between the fibers during spinning, eliminating surface fuzz and producing an even denser, smoother yarn. Fabric made from compact combed cotton pills minimally even after many washes, holds color across multiple seasons, and retains its shape reliably. This is the top premium tier. Look for it on spec sheets labeled "loop-back, compact combed" or similar. Highest wholesale price point.
Practical guidance on choosing a spinning grade: for print-run merch and volume e-commerce production, carded cotton hits the optimum balance of cost and durability. For premium capsule collections, children's clothing, pyjamas, and any brand positioning on quality, choose combed or compact combed cotton. Open-end cotton makes sense only for single-season promotional runs where price is everything.
How Much French Terry Fabric Do You Need Per Garment?
Standard roll width is 175–185 cm (approximately 69–73 in), with 1–2 cm (about ¾ in) of selvedge that cannot be used for cutting. Fabric consumption per unit varies considerably with scale: individual cutting layouts waste more fabric, while production runs allow patterns to nest tightly, reducing consumption per piece by 20–30%.
Individual cutting (one garment per layout):
Production run of 10–50 units in one style (industrial nested layout):
At 100+ units, multi-size marker making can reduce fabric consumption by a further 5–10%.
Cuffs, waistbands, and neckbands are cut from 1x1 rib or 2x2 rib knit at 30–40 GSM heavier than the main fabric. Allow 0.2–0.3 m (approximately ¼ yd) of rib knit per garment. In production runs, cuffs are often partially cut from large offcuts of the main fabric, which reduces rib knit consumption.
Yardage buffer: add 15% on top of your calculated requirement for individual cutting, or 5–10% for production runs (to account for quality rejects, selvedge variation, and consistent cutting allowance). Knit fabric must always be cut on the grainline — off-grain offcuts cannot be used in seams.
Wholesale vs. Retail Pricing
Retail pricing at mainstream online marketplaces typically runs two to four times the wholesale price for equivalent fabric. For brushed fleece in 100% cotton at standard weights, retail prices per meter can easily reach $15–22/m ($14–20/yd), depending on the platform and seller.
At wholesale, two-thread french terry starts at the lower end of the price scale, three-thread loop-back comes in at a moderate premium, and three-thread brushed fleece in quality fiber blends sits at the higher end of wholesale pricing. Interlock knit is broadly comparable to two-thread french terry in wholesale cost.
For a production run of 5–10 garments, the savings from buying at wholesale rather than retail are meaningful. For print merch and volume runs of 50+ units, wholesale pricing pays back from the very first batch — the margin difference is significant enough that retail purchasing for any production volume above a handful of pieces is difficult to justify.
Fabric Recommendations by End Use
Everyday layering piece (hoodie, sweatshirt, lightweight track suit worn under a jacket): two-thread french terry, 210–220 GSM, 75/25 cotton/polyester, black. Transitional-season weight, polyester content keeps the garment in shape, works across a wide range of styles.
Autumn/winter premium range (hoodies, cardigans, structured sweater dresses): three-thread loop-back fleece, 310 GSM, 100% cotton, denim. Carded loop-back construction gives a clean, dense texture; 100% cotton performs well for print work and feels excellent against skin.
Winter merch production runs from 20 units upward (hoodies, track suits, print-ready pullovers): three-thread brushed fleece, 340 GSM, 65/35 cotton/polyester. Winter-appropriate weight; the blended fiber content holds shape reliably after repeated washing.
Long-sleeve tops, turtlenecks, base layers, and children's clothing: interlock knit, 205 GSM, 100% cotton, black. The identical two-faced structure finishes neatly at mock necks and cuffs; 100% cotton is suitable for children and sensitive skin.
The full catalog with filters by GSM, fiber content, and roll width is available in the French Terry section. Individual collections: two-thread french terry, three-thread french terry, interlock knit. The catalog includes 600+ SKUs with photography and full spec sheets.
Common Mistakes When Buying Sweatshirt Fabric
A few recurring errors that show up most often with first production runs.
Ordering by photo without checking GSM. In a product image, 240 GSM and 320 GSM three-thread french terry look identical. After the garments are made, a winter hoodie cut from 240 GSM fabric is too cold to sell at full price and ends up on clearance. Always verify the GSM figure on the spec sheet — never rely on the photo alone.
Ignoring fiber content to save money. A listing marked "knit fabric" without a stated percentage breakdown almost certainly contains 50–60% rayon (viscose) or low-grade polyester. After three to five washes the garment loses its shape. Only buy fabric with a clearly stated fiber composition.
Cutting without pre-shrinking. 100% cotton fabric can shrink 3–5% on first wash. If you cut straight from the roll, finished garments will come out a full size smaller. Before cutting, pre-wash the fabric at 40–60°C (105–140°F) and allow it to dry fully.
Mismatched fiber content between the body and the rib trim. Cuffs, waistbands, and neckbands in rib knit must share the same fiber composition as the main fabric. If they don't, differential shrinkage causes the cuffs to ripple and buckle after washing. Buy your rib knit from the same fabric range as your main body fabric.
Choosing brushed fleece for print work. The pile doesn't affect the face of the fabric directly, but with fine-detail artwork on lightweight brushed fleece, the pile structure can telegraph through and soften edges. For sharp, high-resolution prints, use three-thread loop-back or dense two-thread french terry.
Ordering exactly the calculated yardage with no buffer. Knit fabric must be cut on grain — off-grain offcuts are unusable. Always add 5–10% to your order for production runs and 15% for individual cutting, to cover rejects, selvedge, and cutting variance.
Frequently Asked Questions
Three-thread brushed fleece at 280–300 GSM in an 80/20 cotton/polyester blend. This is the industry standard for autumn/winter wardrobe staples: hoodies, track suits, and cardigans.
Three-thread loop-back at 240–260 GSM can be used for lightweight transitional pieces. Three-thread brushed fleece is not a good summer choice — it will be uncomfortably warm. For summer, use two-thread french terry at 180–220 GSM or interlock knit.
These are cotton yarn spinning methods, listed from most affordable to most premium. Open-end (OE/rotor-spun) is the lowest cost — the yarn is denser and rougher, acceptable for everyday wear and promotional merch. Carded cotton is the mass-market standard, slightly firmer than combed but the fabric that drives the majority of mainstream retail production. Combed cotton uses longer-staple fiber with an additional combing step; the yarn is smooth and strong, with a slight sheen — premium quality and noticeably better color retention. Compact combed cotton is an enhanced version of combed where air is removed from the yarn bundle, eliminating surface fuzz and producing the smoothest, densest yarn available — this fabric pills minimally even after many washes and holds its shape over multiple seasons. It is the top-tier option. On supplier spec sheets the spinning grade is typically listed alongside the construction: "loop-back, carded" or "loop-back, compact combed." For the best longevity, choose compact combed cotton; for a mid-budget project, carded cotton is the right call; for minimum cost on short-life promotional pieces, open-end cotton is acceptable.
Only for specific performance applications: activewear hoodies and sweatpants for training, moisture-wicking styles, and technical athletic suits. For everyday casual wear, 100% polyester is not appropriate — it doesn't breathe and becomes uncomfortable against the skin during normal activity.
Quality 100% cotton fabric at 300 GSM will withstand 40–60 washes before showing noticeable wear. A cotton/polyester blend will last longer — typically 80–100 washes — given consistent care. These figures assume washing at 30–40°C (85–105°F) without a heavy spin cycle.
Two-thread french terry in 100% cotton at 200–220 GSM, or interlock knit at 200–220 GSM. Both are hypoallergenic, soft, and hold their shape through a child's growth. For winter children's suits, move to 280–300 GSM brushed fleece in 100% cotton.
Loop-back (unbrushed) gives a cleaner, smoother inside surface, neater seam construction, and a sharper base for print or embroidery on the face. Brushed fleece is warmer to the touch but the pile can interfere with clean seam finishing and fine print detail. For everyday winter hoodies and track suits, brushed fleece is the standard choice. For sweater dresses, cardigans, and premium-positioned styles, dense loop-back is generally preferred.
Yes — sweatpants and track suits are one of the primary end uses for this fabric, on par with hoodies. For winter bottoms and suits, use three-thread brushed fleece at 280–320 GSM. For transitional-season bottoms, use three-thread loop-back at 240–280 GSM. For slim-fit or tapered joggers and leggings, add 3–5% spandex (elastane) to the fiber blend.