BJJ Gi Patching Regulations - IBJJF vs. UAEJJF
We've all experienced it. That dreaded moment when - after months of training, weeks of cutting weight, and too many hours getting your gi perfectly patched up - the gi checker says it's illegal. Not the fit... which is an entirely different crisis... your patch.
Out come the scissors, and your beloved academy patch, brand logo, or dedication to your mom doesn't get its deserved publicity on the mat.
That sucks. To help you avoid this situation, we decided to give you the short-and-sweet on gi patching regulations for the major jiu jitsu promotions. Read on...
IBJJF
As you can see, IBJJF gives you plenty of surface area for gi patches. It is important to note the areas in which you cannot patch: below the elbows, underneath the belt, around the knees, and 15cm from the bottom of the pant hem. The reasoning behind this that these are "high-grip" areas, and patches - which are often made from material that has less texture, making it harder for your opponent to grab - in those areas would provide an unfair advantage. You might as well be fighting no-gi in that case. In my personal experience at IBJJF tournaments, I've seen more people fail gi check for fit and wear (tattered belt or lapel) than I have for excessive patching.
UAEJJF
You'll note that UAEJJF has similar patching regulations, for the same reason. There are some key differences, however. Gi brand logos (but no other patches) are allowed within the 15cm area from the bottom of the hem, but they must be fabric patches, not embroidered, and cannot be more than 36cm square. Be careful with embroidered gi brand logos in any other area of the gi (thigh or jacket skirt, for example)... sometimes they'll pass you through, sometimes not. Patches along the side of the pant cannot be wider than 10cm. UAEJJF gi checkers are also very picky about BJJ patches that just barely creep into the non-patching zone (especially around the knees).
Better Safe Than Sorry
Most local promotions follow the IBJJF and UAEJJF gi regulations, but be sure to check each event's rulebook to make sure. Also, if you happen to have a gi that you think might be borderline, don't assume the gi checker will give you the benefit of the doubt. It's always wise to bring a spare, ultra-minimally adorned gi whenever you compete... just in case.
Train on. Oss.
Pakistan entered the market in the late 1990's, but didn't obtain widespread acceptance - due to political stigma centered around the entire Middle Eastern region in the early 2000's - until around 2009. Some of the first brands to import Pakistan-made gis were Lucky and Ouano. In the last decade, Pakistan has made dramatic progress in their quality and manufacturing efficiency. In particular, they produce a superior cotton fabric, which for all-cotton gis (both jacket and pants) puts them ahead of the curve. It is estimated that approximately 70% of the gis in the U.S. market are made in Pakistan. However, they have not yet mastered the 100% preshrinking process, so expect these gis to shrink slightly.
Despite a long-standing tradition of kimono manufacturing - for all kinds of martial arts - China came to the Brazilian jiu jitsu much later. However, they are known to produce some of the most durable gis in the market. Typically, Chinese gis are 100% preshrunk, and fabric manufacturers there are incredibly adept at producing specialty fabrics, including Ripstop, hemp, and bamboo. Pakistan still beats them on the quality - and softness - of their cotton, however. It is estimated that China produces approximately 20% of the gis in the U.S. market. 
However, you may have noticed that the fabric on some gis look a little different. That's because there is actually a difference in weaves. This has to do with the manner in which the "weft" is woven through the "warp." The warp refers to the set of threads, aligned parallel to each other, that are stretched on the loom first, before the weft is woven through. 
