Daruma Green Store · Gear & Materials · ~950 words · 5 min read
Most BJJ athletes assume their gi is cotton. Most of the time, it isn't.
The word cotton carries weight in martial arts. It implies tradition, breathability, natural feel. It's what gis were made of for decades. When you see 'cotton gi' on a product page, you picture something substantial and honest.
But the BJJ gear industry has quietly shifted — and most athletes haven't noticed because nobody is talking about it. If you look closely at the label inside your current gi, you might find a number that changes how you see it.
The Label Problem
Walk into any BJJ gym and look at the gis on the rack. Ask athletes what their gi is made of. Almost everyone will say cotton. Most of them are wrong — not because they're not paying attention, but because the industry has made it easy to miss.
A gi labelled as a 'cotton gi' can legally contain a significant percentage of synthetic fiber as long as cotton is the dominant material. 50% cotton / 50% polyester can still be marketed as a cotton gi in most jurisdictions. The label is technically accurate. It is not the full picture.
A gi marketed as cotton can be 50% polyester. The label is legal. It is not the same thing as being honest.
Why Brands Add Polyester
This isn't a conspiracy. It's economics — and once you understand the manufacturing pressures, the behaviour makes sense, even if the outcome doesn't serve the athlete.
Cost. Polyester is significantly cheaper than quality cotton at scale. Adding synthetic fiber to a gi reduces material cost while maintaining acceptable weight and texture on first contact. The saving goes to the manufacturer's margin, not to you.
Weight consistency. Cotton varies naturally by harvest, region, and season. Polyester is uniform. Blending the two gives manufacturers more control over the final fabric weight and appearance — which matters for production consistency across large runs.
Shrink resistance. Pure cotton gis shrink. Managing that is a genuine challenge — athletes need to know exactly what size to buy and how much pre-shrinkage to factor in. Adding polyester reduces shrinkage, which simplifies sizing and reduces return rates. It also reduces breathability, increases heat retention, and creates the odor conditions we've written about elsewhere.
Durability perception. Polyester doesn't pill or abrade the way lower-grade cotton does. A blended gi can feel durable on first inspection even if the long-term performance doesn't match. First impressions sell gis. Long-term performance earns loyalty — and most brands are optimising for the former.
What Polyester Actually Costs You
The economics make sense for the brand. They don't make sense for you.
Polyester traps heat. In a BJJ context — close contact, high exertion, extended rounds — that means your body works harder to regulate temperature. You fatigue faster. You notice it most in the later rounds, when you're already tired and your gi feels heavy and hot.
Polyester also creates the odor conditions we've covered in detail elsewhere. The fiber structure is rough at a microscopic level, bacteria embeds effectively, and standard washing cycles don't fully clear it. The smell comes back faster each time — not because of how you wash, but because of what the fabric is doing.
And polyester degrades differently from cotton. Pure cotton, even as it softens and wears, does so relatively uniformly. Polyester-cotton blends tend to degrade unevenly — the synthetic threads hold while the cotton breaks down around them, creating an inconsistent fabric texture that looks worn before it's structurally compromised.
How to Read What You're Actually Buying
The composition label is always there. It's usually sewn into the inside of the collar or the lower hem of the jacket. Here's what you're looking for:
- 100% Cotton — what a pure gi looks like
- 50/50 Cotton/Poly blend — common mid-market
- ~30% Cotton with high poly — budget category
| Composition | Breathability | Odor Resistance | Lifespan | True cost |
|---|---|---|---|---|
| 100% Natural (hemp) | Excellent | Natural, inherent | 5-8 years | Lowest over time |
| 100% Cotton | Good | None | 2-3 years | Medium |
| Cotton/Poly 50-50 | Moderate | Poor | 2-3 years | Medium + discomfort |
| High Poly blend 70%+ | Poor | Very poor | 1-2 years | Highest over time |
Why This Is Hard to Talk About
We want to be careful here. We're not saying that brands using polyester blends are dishonest. Many of them are transparent about their composition if you look for it — it's in the label, sometimes in the fine print of the product page.
What we're saying is that the default in the industry has shifted toward synthetic content without a corresponding shift in how products are marketed. 'Cotton gi' has become a category name rather than a material description. And most athletes — who are thinking about their training, not textile manufacturing — don't know to look.
The question isn't whether brands are lying. The question is whether the label tells you what you actually need to know before spending EUR 120 on gear you'll wear every day.
What to Look For — and What to Ask
Before you buy any gi, do three things:
- Find the composition label. It's sewn into the garment — usually collar or hem. If you can't find a composition percentage, that's already a signal.
- Look for the actual percentages. Not 'cotton blend' or 'premium fabric.' The exact split: 70% cotton / 30% polyester. If a brand won't publish this clearly, ask them directly before buying.
- Ask what the polyester content is doing. If a brand tells you it's for durability or shrink resistance, that's a reasonable answer. If they can't answer, that's also information.
Where Daruma Stands
Our Hemp Gi is 100% hemp. No blending. No synthetic content. Not because we're purists, but because hemp doesn't need a polyester crutch — it's already stronger, more breathable, and more odor-resistant than any blend on the market.
Our Bamboo Rashguard is 95% bamboo / 5% spandex. The spandex is there for stretch and recovery — it's a functional addition that enables the fit, not a cost-reduction measure. We publish these numbers clearly because we think you should know exactly what you're buying.
The standard we hold ourselves to is simple: if we wouldn't be comfortable publishing the composition on the front of the product page, we shouldn't be selling it. That's it.
100% hemp. Nothing hidden. No shortcuts.
Read the label. Know what you're training in.
