Most sweatshirts are made from cotton, polyester, or a cotton-polyester blend, typically constructed with a fleece or French terry knit.
A sweatshirt’s fabric determines everything about how it feels, how long it lasts, and how it will hold up in the wash. While nearly all sweatshirts share a thick, knit construction, the fiber blend underneath separates the soft everyday pullover from the durable weekend workhorse.
The Core Fibers Behind Every Sweatshirt
Cotton and polyester carry the bulk of the load. Cotton delivers softness, breathability, and that familiar broken-in feel. Polyester steps in for durability, shape retention, and quick-dry performance. Most manufacturers blend them to balance comfort and longevity.
Two fabric structures dominate the market:
- Fleece — a brushed, fuzzy interior that traps air for warmth. Heavier and cozier, this is the classic cold-weather sweatshirt.
- French terry — a looped back with a smooth face. Lighter than fleece, it drapes better and breathes more easily.
Beyond the big two, you’ll often find small percentages of spandex/elastane for stretch and recovery, or rayon for a softer drape, depending on the garment.
Most Common Cotton-Blend Ratios
Rarely is a sweatshirt 100% cotton anymore. According to Threadless’s product documentation, current sweatshirt compositions show a clear pattern across fleece and French terry styles.
| Fabric Type | Typical Composition | Best For |
|---|---|---|
| French Terry Pullover or Zip-Up | 55% cotton / 45% polyester | Midweight layering, transitional weather |
| Fleece Pullover (Solid) | 52% cotton / 48% polyester | Classic warmth, everyday wear |
| Fleece Pullover (Heathered) | 60% cotton / 40% polyester | Washer-friendly, rugged durability |
| Fleece Crew (Triblend) | 50% polyester / 37.5% cotton / 12.5% rayon | Soft drape, vintage-washed feel |
The triblend option is worth noting — the rayon content gives it a silkier hand than a standard crew, at the cost of some structure. If you’re shopping for a premium made-in-America option, these cotton-heavy blends are where the quality sits. Check our roundup of the best American-made sweatshirts to see how these fabrics perform in real garments.
How Fabric Choice Affects Care And Comfort
Blends behave differently from pure cotton in three key ways: shrinkage, stretch, and heat tolerance. Polyester holds shape better and dries faster, which is why most athletic-cut sweatshirts lean heavier on it. Cotton shrinks more readily in hot water, so a high-cotton garment needs gentler washing.
The fleece vs. French terry distinction matters for comfort too. Fleece’s brushed interior traps body heat, making it the better choice for winter. French terry’s looped back allows more airflow — Seamwork’s fabric guide highlights it as a lighter, more breathable alternative that still reads as a sweatshirt.
One caveat: polyester can feel less breathable than cotton against the skin. If you have sensitive skin or run hot, a cotton-dominant blend is the safer bet.
FAQs
Are all sweatshirts made of cotton?
No. While cotton remains the most common base fiber, most sweatshirts today are cotton-polyester blends. Pure cotton sweatshirts exist but are less common, and they tend to shrink more and hold their shape less well than blended versions.
What is the difference between fleece and French terry?
Fleece has a brushed, fuzzy interior that traps air and provides more warmth; French terry has a smooth face with loops on the back and is lighter and more breathable. The seasonal “sweatshirt weight” question comes down to which of these two structures you pick.
How should I wash a cotton-polyester sweatshirt?
Wash in cold water and tumble dry low to prevent shrinkage and preserve the fabric’s shape. High-heat drying is the fastest way to ruin a cotton-heavy blend, and it can also degrade the elastic in spandex-containing styles.
References & Sources
- Threadless Help Center. “What are your products made of?” Lists current sweatshirt fabric compositions by style.
- Seamwork. “All About Sweatshirt Fleece” Explains fleece vs. French terry construction and weight differences.
- Wikipedia. “Sweatshirt” Provides general background on the garment’s history and typical constructions.