Two gis can share the same GSM number and feel completely different, and a gi with a glamorous "weave name" is often just a standard weave in a nicer box. Once you understand what weave and GSM really do, you can spec the right gi for a child, a competitor or an instructor with total confidence.
GSM: What It Actually Means
GSM stands for grams per square metre: the density of the fabric, not the total weight of the gi. That's the thing people get wrong most often. A higher GSM means a denser, heavier, more hard-wearing cloth, and a lower GSM means a lighter, more breathable one. It's a useful shorthand for weight and durability, though, as you'll see below, it isn't the whole story.
Pearl Weave: The Modern Standard
Pearl weave is what the large majority of gis are made from today, and for good reason. It's tightly woven, which makes it strong for its weight, comfortable, and, crucially, it shrinks very little. Because the weave is tight, you get a lot of durability without a lot of extra weight, which is why it's the default for everything from lightweight training gis to competition kimonos. We build pearl weave in 350, 400 and 450 GSM.
Gold Weave: The Instructor's Premium
Gold weave is the heavier, more structured, premium cloth, the one that gives a gi presence and authority on the mat. Here's the honest part most brands won't tell you: gold weave shrinks more than pearl, because its threads sit more loosely apart than the tightly woven pearl. We pre-shrink and sanforise our fabric to control that, but it's in the nature of the weave. Choose gold for the feel and the prestige, not because it's somehow stronger or more competition-legal, because it isn't.
Trousers: Twill vs Ripstop
The trousers are a separate decision from the jacket. In plain terms:
- Twill (light or heavy) is the most comfortable option, but it loses its shape faster over time.
- Ripstop is stiffer, holds the trouser's shape for much longer and resists tearing better. Worth knowing, though: "ripstop" does not literally stop rips. It's more tear-resistant, and trousers still wear at the knees and can tear at stress points if the size is too small.
- Diamond Ripstop is our reinforced build for competitors who want the most durable, shape-holding trouser.
The Break-In Truth
Every gi breaks in, a bit like a leather jacket. Heavier builds start stiffer and get more comfortable the more you train in them, while lightweight gis are usually comfortable straight out of the box. Heavier fabric also lasts longer and costs more. Neither is better; they're different tools for different athletes, which brings us to the part that actually matters.
Which Weave and Weight for Which Athlete
This is how we spec gis on the factory floor, every day:
| Athlete / use | Jacket | Trousers |
|---|---|---|
| Everyday, spare gi, summer, lightweight lovers & kids | 350 GSM pearl | 230 GSM twill (kids) · 300 GSM twill (adults) |
| Women & lightweight men | 400 GSM pearl | Women: lighter ripstop or twill · Men: heavy twill or medium ripstop |
| Professionals & competition | 450 GSM pearl | Diamond Ripstop |
| Instructors (for authority & presence) | Gold weave | Heavy ripstop or twill |
The most common mistake we fix: putting very heavy ripstop trousers or a heavy-GSM jacket on kids, women or lightweight athletes. It's uncomfortable, restrictive and unnecessary, and lighter builds serve them far better. If you're not sure what to spec, just ask us on WhatsApp →
The "Fancy Weave Name" Game
You'll see gis marketed with exotic weave names: platinum, honeycomb, hyper, crystal, and so on. Some of those tweaks are genuinely functional, some are purely visual. But here's the straight talk from the loom: they almost always come back to a standard weave, and they're not worth paying 1.5× the price for something that costs about 1.2× to actually make. We won't put a marketing premium on a renamed weave. You pay for the cloth and the craft, not the label.
Is Your Gi IBJJF-Legal?
If your customers compete, this matters. Here's an honest summary of the current IBJJF uniform rules (always check the official IBJJF rulebook before an event, as they do update it):
- Colour: white, royal blue or black only, and the jacket and trousers must match.
- Material: a woven cotton or cotton-like jacket (pearl or gold weave). Ripstop is allowed for the trousers, but not the jacket.
- Collar: between 1 and 1.3 cm thick and 4.5–5 cm wide (EVA foam inside is fine within that limit).
- Fit: sleeves and trousers must reach close to the wrist and ankle, with enough sleeve opening for a grip check. The tolerance was tightened to about 2 cm in a recent update.
- GSM: yes, there is a spec. The IBJJF's official manufacturer manual sets the jacket at 380–650 g/m² and the trousers at 220–300 g/m². (The "no GSM rule" line you'll read online refers to competition inspection, where officials check collar, sleeve and fit rather than weighing the gi, but the manufacturing standard does set these ranges.) Note that a 350 GSM jacket is a light training weight, just below the 380 competition minimum, which is why competition gis use 400–450 pearl or gold.
Every gi we make can be built to IBJJF-legal specification. See our gi range or tell us the event and we'll make sure your build passes inspection.
Still Not Sure What to Order?
That's normal. The right answer depends on your athletes, your climate and your brand. Send us who you're making gis for and we'll recommend the exact weave and GSM, then you can weigh it against what it costs to make and how ordering works.