Key production numbers
280 GSM directionA versatile mid-weight option for layering, transitional weather and lower shipping mass.
320 GSM directionA denser option for structured silhouettes and cooler-weather positioning.
GSM limitationWeight does not describe fibre, knit, brushing, softness, recovery or durability.
Approval ruleCompare the intended fabric in a finished sample and after an agreed wash test.
Choose by product intent
A 320 GSM hoodie is generally heavier and more structured than a comparable 280 GSM hoodie, but GSM alone does not determine quality. Fibre, knit density, brushing, yarn, finishing and pattern can make equal-weight fabrics behave differently.
Choose 280 GSM for easier layering and a wider climate range. Choose 320 GSM for a denser hand and stronger silhouette. Always approve the exact fabric and garment sample.
Wear experience
A well-developed 280 GSM fleece can feel substantial without becoming bulky. It suits transitional weather, active styling and shipping-sensitive programs. A 320 GSM construction can deliver more warmth and visual weight.
Comfort also depends on the inside finish. Brushed fleece differs from French terry, while polyester content changes recovery, drying and surface appearance.
Pattern and sewing implications
Heavier fabric increases seam bulk around the hood, pocket, cuff and hem. Needle, thread, seam allowance and reinforcement may need adjustment. Hood geometry and neckline support become more important.
Rib must recover strongly enough to balance the body. Fit approval in a lighter substitute can be misleading, so bulk sampling should use the intended fabric.
Decoration and approval
Smooth stable surfaces generally support clean printing, while fluffy surfaces may need different preparation. Embroidery needs suitable backing and tension to prevent distortion.
Compare swatches for composition, weight tolerance, stretch, recovery, colour and finish, then compare garments for drape, hood balance, seam bulk and wash response. Record the approved fabric code on the order.
What GSM measures—and what it does not
GSM means grams per square metre: the mass of a square metre of fabric. Moving from 280 to 320 GSM is an increase of about 14% in nominal fabric mass, assuming the same area. It does not prove that one fabric contains better cotton, has tighter knitting, resists pilling or will recover after washing.
Compare composition, yarn, knit structure, usable width, finish, shrinkage, colourfastness, stretch and recovery alongside weight. Cotton quality guidance distinguishes measurable fibre properties, while finished-fabric testing checks the performance that a brand and customer actually experience.
French terry and fleece can reverse expectations
French terry has visible loops on the inside and can feel breathable and adaptable. Brushed fleece raises the inside surface for softness and insulation. A well-developed 280 GSM brushed fleece may feel warmer than a 320 GSM unbrushed terry, while a compact 320 GSM terry may look cleaner and more structured.
Specify inside finish explicitly instead of ordering by GSM alone. Ask for face and back photos, composition, weight tolerance and a physical swatch. If the product description promises brushed fleece, record brushing level and approve the surface because excessive brushing can change appearance and pilling behaviour.
Fit and silhouette: how weight changes the pattern
A 280 GSM fabric usually drapes more easily, which can suit relaxed layering. A 320 GSM fabric can hold an oversized or boxy silhouette more firmly. However, the effect depends on density, recovery and pattern dimensions, so simply substituting a heavier fabric into an approved light-fabric pattern can change the neckline, hood balance and pocket position.
Approve shoulder width, chest, body length, sleeve shape, hood opening, pocket position, cuff and hem in the intended fabric. If a brand changes weight after fit approval, the pattern maker should review seam bulk, hood attachment, rib tension and finished measurements before bulk production.
Warmth, climate and customer use
Choose fabric around how the customer will wear the hoodie. A 280 GSM layer can work across more seasons, indoors and in mild climates. A 320 GSM garment can support cooler conditions and a premium heavyweight story, but it may feel too warm for some markets or increase storage and shipping volume.
Do not market warmth from GSM alone. Fibre composition, trapped air, brushing, garment fit and layers underneath all contribute. Describe the product accurately—for example mid-weight French terry or heavyweight brushed fleece—and confirm the final claim from the approved garment.
Printing and embroidery on 280 vs 320 GSM
Both weights can support screen printing and embroidery when the surface and construction are appropriate. A smooth stable face makes print control easier. Thick or fluffy fabric may require artwork adjustment, additional print preparation or different curing control. Large solid prints can also alter hand feel and stretch.
Embroidery should be tested with the planned backing, needle, stitch density and placement. A heavy design can distort a soft 280 GSM fabric, while a dense 320 GSM body still needs correct hooping and tension. Approve a strike-off or garment sample rather than relying on a digital mock-up.
Material and freight cost implications
If every other factor is equal, 320 GSM uses more mass per square metre than 280 GSM. The unit-cost effect is not a fixed percentage because fabric price per kilogram, garment area, marker efficiency, shrinkage allowance, minimum purchase and waste also matter. Heavier finished cartons can also change freight calculations.
Request both ex-factory and landed-cost comparisons using the same pattern, composition, quantity and destination. If the heavier option supports a higher retail position or lower return risk, a higher manufacturing cost may still be the better commercial decision.
Sampling and testing checklist
At swatch stage, record supplier code, composition, nominal GSM, tolerance, width, colour, finish, stretch and recovery. At garment stage, review drape, hood balance, seam bulk, rib recovery, decoration and comfort. Agree on the conditioning and measurement method used when checking weight because moisture and sampling method can affect results.
Run an agreed wash assessment before bulk approval when shrinkage, spirality, colour, pilling or print durability matters. Keep the approved fabric reference, garment sample and test expectations connected to the purchase order so a later substitute cannot be accepted only because it has the same GSM.
Decision framework for a first streetwear order
Choose 280 GSM when versatility, layering, softer drape or lower shipment mass is central. Choose 320 GSM when structure, denser hand feel and cooler-weather positioning are more important. For premium heavyweight programs beyond 320 GSM, recheck hood construction, rib, seam bulk and freight rather than treating weight as a simple upgrade.
The safest first-order decision is to compare two swatches and, where budget permits, two samples built from the same measurements. Score each option for fit, hand feel, decoration, wash response, target climate, retail position and landed cost. The winning fabric is the one that supports the complete product brief.
Hoodie fabric weight decision table
| Decision | 280 GSM direction | 320 GSM direction | Verify before bulk |
|---|---|---|---|
| Positioning | Versatile mid-weight | Denser heavyweight story | Target customer and retail tier |
| Silhouette | More fluid or layered | More structured | Sample in intended fabric |
| Climate | Mild or transitional use | Cooler-weather use | Fibre and inside finish |
| Inside finish | Terry or brushed fleece | Terry or brushed fleece | Approve surface and hand feel |
| Sewing | Moderate seam bulk | Closer bulk and needle control | Hood, pocket, cuff and hem |
| Decoration | Watch distortion on dense artwork | Watch surface and curing | Garment strike-off or sample |
| Freight | Lower nominal fabric mass | Higher nominal fabric mass | Finished carton weight and volume |
| Quality | Not defined by GSM alone | Not defined by GSM alone | Composition, wash and performance |
Frequently asked questions
Is 320 GSM always warmer?
Usually, but composition and inner finish also matter.
Which is best for streetwear?
Both work: use 320 GSM for density and 280 GSM for versatile layering.
Can GSM vary?
Yes. Agree on a measurable tolerance and approval method.
Is 280 GSM too light for a premium hoodie?
No. Premium positioning depends on fibre, knitting, finish, pattern, construction and branding as well as weight.
How much heavier is 320 GSM than 280 GSM?
The nominal fabric mass per square metre is about 14% higher, but finished garment weight also depends on pattern area, rib, hood layers, pockets and trims.
Is 320 GSM better for embroidery?
Not automatically. Both weights require suitable backing, stitch density, hooping and tension, tested on the intended fabric.
Which weight costs less to ship?
A comparable 280 GSM garment usually has lower material mass, but the carrier charges from finished carton weight, volume, route and service.
Should I approve a hoodie using substitute fabric?
Only for an early fit check. Final approval should use the intended fabric because weight, stretch, recovery and finish affect fit and decoration.
Sources and verification
Official and industry-primary references used to verify standards, regulations and definitions in this guide.
CottonWorks — cotton fibre classification ↗CottonWorks — textile quality testing ↗Textile Exchange — Materials Market Report 2025 ↗