The uniform will be subjected to great stress during training (friction with the ground, grapples with a partner, etc.) which will really put the fabric and strength of the seams to the test. Several factors should also be taken into consideration when looking at the durability of the fabric:
A Brazilian jiu-jitsu uniform should be mainly composed of cotton for thicker, more durable fabric. The inclusion of polyester in the fabric reinforces the fabric further, also making it lighter and faster-drying (cotton holds a lot of moisture).
Fabric weight (known as grammage)
Generally expressed in gsm or g/m², this is the weight of the fabric in grams over an area measuring 1 metre by 1 metre. Generally, for fabrics of identical composition, the heavier the fabric the thicker and more durable it is. Most fabrics used in Brazilian jiu-jitsu uniforms range from 350gsm to 550gsm, but lighter or heavier fabrics may also be used.
The quality of all the threads used in making uniforms may vary. When making thread, some processes result in a more uniform and more durable thread. Therefore different types of weave (see below) will have different durability depending on the thread used.
You'll hear about "single/double/pearl/diamond/gold… weave." This describes the woven motif used in manufacturing the fabric. Naturally, a single weave will be lighter than a double weave as the construction of the motif uses less thread, but it will thus be less durable. The other types of weave are "hybrid," allowing a better compromise between durability and light weight, "pearl weave" is widely used. Shrinkage in the wash may also vary according to the type of weave.