GSM stands for Grams per Square Meter. Basically, this form of measurement is similar to thread count in bedsheets. The higher the GSM count means the thick and more fluffy the product. Generally, on the lower end of the scale are GSMs that are about 230. These make for pretty thin cotton materials but are also usually incredibly affordable. The normal range is about 400 GSMs, which are a little bit like the products that you use for everyday use in your bathroom. Products that have a GSM of over 400 are the Cadillac of cotton materials and are considered to be incredibly plush and high end. While GSMs that are over 400 are very soft, they might be a little difficult to pack into a bag, so it’s important to keep that in mind when selecting the product for you. Anything over 400 might be better off being used poolside.