When you’re building an apparel brand, the fabric you choose is one of the most consequential decisions you’ll make. It affects cost, comfort, durability, and how your customers perceive your brand. But here’s the problem: most new brand owners get lost in terminology the moment they start talking to manufacturers. GSM. Knit vs. woven. Combed vs. carded. It adds up fast.
This guide cuts through the noise. We’ll break down fabric types, explain what GSM actually means for your product, and show you how to use this knowledge to make smarter sourcing decisions.
What Is GSM?
GSM stands for Grams per Square Meter. It’s a measurement of fabric weight — specifically, how many grams one square meter of fabric weighs. The higher the GSM, the heavier and denser the fabric. The lower the GSM, the lighter and more breathable it is.
Here’s a practical breakdown:
| Fabric Type | Typical GSM Range | Best Used For |
|---|---|---|
| Sheer / Lingerie | 30 – 80 GSM | Underwear, lingerie, linings |
| Lightweight | 80 – 120 GSM | T-shirts, blouses, summer dresses |
| Medium Weight | 120 – 200 GSM | Shirts, pants, casual jackets |
| Heavyweight | 200 – 400 GSM | Hoodies, sweatshirts, winter wear |
| Ultra Heavy | 400+ GSM | Canvas, workwear, heavy jackets |
A standard cotton T-shirt typically falls between 120–160 GSM. A heavyweight hoodie usually sits around 300–400 GSM. Knowing this gives you a solid reference point when discussing options with your manufacturer.
Knit vs. Woven: The Fundamental Divide
All fabrics fall into one of two categories: knit or woven. Understanding the difference is essential.
Knit Fabrics
Knit fabrics are made by interlocking loops of yarn. They have natural stretch, are more forgiving on fit, and tend to be softer. They’re also easier to work with during production, which can translate to lower manufacturing costs.
Common knit fabrics:
- Cotton Jersey – The standard T-shirt fabric. Soft, breathable, with moderate stretch. Usually 120–160 GSM.
- French Terry – Looped on one side, smooth on the other. Great for sweatshirts and lightweight loungewear. 250–350 GSM.
- Rib Knit – Highly elastic, used for cuffs, collars, and trim. Usually 180–250 GSM.
- Interlock – Slightly thicker than jersey, smooth on both sides. Good for premium T-shirts and dresses.
- Ponte di Roma – A double-knit fabric that’s structured yet stretchy. Popular for dresses and fitted styles. 250–350 GSM.
Woven Fabrics
Woven fabrics are made by crossing horizontal and vertical threads. They have little to no stretch, hold shapes well, and tend to be more durable. They require more precision in cutting and sewing, which can increase production time and cost.
Common woven fabrics:
- Poplin – Lightweight, smooth, and crisp. Classic shirting fabric. 100–150 GSM.
- Twill – Diagonal weave pattern. Durable and versatile. Used for chinos, jackets, and workwear. 150–300 GSM.
- Oxford – Textured, slightly heavier. Common in casual button-down shirts. 150–200 GSM.
- Canvas – Heavy, tightly woven. Used for bags, workwear, and structured outerwear. 300–600 GSM.
- Denim – Sturdy twill weave, typically 300–500 GSM. Jeans, jackets, skirts.
Fabric Blends: Getting the Best of Both Worlds
Most apparel today isn’t made from 100% of one fiber. Blends exist because different fibers bring different strengths. Here’s what you need to know about common blends:
- Cotton-Polyester (CVC or PC) – Cotton combined with polyester. Cotton provides softness and breathability; polyester adds wrinkle resistance and durability. A 60/40 cotton-poly blend is common for T-shirts and casualwear.
- Cotton-Elastane (Spandex) – Adds stretch and recovery. Essential for fitted garments like skinny jeans, leggings, and swimwear. Usually 2–5% elastane content.
- Tri-Blend – Typically cotton, polyester, and rayon. Ultra-soft with a vintage drape. Common in premium casualwear.
- Wool-Polyester – Reduces cost and increases durability while retaining some wool warmth. Used in suiting and outerwear.
Fabric Certifications Every Brand Should Know
If your brand makes any sustainability or ethical claims, the fabric certifications your manufacturer holds matter — a lot. Here are the ones you should be familiar with:
- GOTS (Global Organic Textile Standard) – The gold standard for organic cotton. Covers the entire supply chain from fiber to finished product.
- OEKO-TEX Standard 100 – Tests finished fabrics for harmful substances. Required by many European retailers.
- GRS (Global Recycled Standard) – Verifies recycled content in textiles. Essential if you’re using recycled polyester or cotton.
- BCI (Better Cotton Initiative) – A mass balance system for sourcing more sustainable cotton. Less rigorous than GOTS but more accessible.
Ask your manufacturer for current certificates, not just claims. Verify them on the issuing organization’s website.
How to Specify Fabric to Your Manufacturer
When you approach a manufacturer with your fabric requirements, be specific. Vague descriptions lead to samples that don’t match your vision. Include:
- Fiber content (e.g., 100% organic cotton, 60/40 cotton-poly)
- Fabric construction (jersey, French terry, twill, poplin)
- GSM target
- Certifications required
- Color fastness requirements (wash fastness, light fastness)
- Shrinkage tolerance (usually ±3–5% is standard)
If you’re unsure, start with a reference sample. Send your manufacturer a physical swatch of the fabric you want. Even a photo with specifications is better than nothing.
Common Mistakes New Brands Make with Fabric Sourcing
Choosing GSM that’s too low to hold its shape. Ultra-light fabrics drape beautifully but can look cheap on certain styles. A structured T-shirt needs at least 140 GSM; an oversized drapey tee can go lighter.
Assuming “cotton” means the same thing everywhere. Cotton quality varies enormously. Pima cotton, Egyptian cotton, and upland cotton all behave differently. Know what you’re asking for.
Ignoring shrinkage rates. Always pre-wash or request pre-shrunk fabric for garments that will be washed at home. Unexpected shrinkage is one of the top causes of returns.
Not ordering enough yardage for sampling. Fabric dye lots vary. Order extra fabric upfront — ideally 10–15% more than your initial order — so you can produce replacement units without color mismatches.
Final Thoughts
Fabric is where your brand promise becomes tangible. The right GSM and fiber combination tells your customer exactly what kind of brand you are — before they even read your label. Take the time to understand what you’re specifying, ask hard questions of your manufacturer, and always, always get a sample before committing to bulk production.
Need help navigating fabric sourcing for your brand? Connect with our team — we work with brands at every stage, from first concept to full-scale production.