GSM stands for grams per square meter, which is a standard measurement for fabric weight. It refers to the weight of the fabric if you take a sheet of material which is one meter by one meter square and weigh it in grams. The higher the GSM, the denser and heavier the fabric will be. For example, denim has a much higher GSM than chiffon. GSM is an important consideration when it comes to choosing clothes for specific sports or activities, as it helps to regulate body temperature and maximize performance.

Different fabrics have different average GSM ranges, with lightweight fabrics ranging from 1-150 GSM, mid-weight fabrics ranging from 150-250 GSM, and heavyweight fabrics ranging from 250+ GSM. For instance, chiffon, organza, voile, and taffeta are lightweight fabrics, while velvet, cambric, sateen, and chambray are mid-weight fabrics, and wool felt, denim, hessian, and twill are heavyweight fabrics.

While a higher GSM fabric may be thicker and absorb more total liquid, it does not necessarily mean that it is better. Other factors, such as the weave type, construction, and yarn quality, also determine the quality of a fabric. When choosing a fabric, it is important to consider the purpose of the purchase and the intended usage of the material at hand.