What GSM actually tells you about a towel
Weight is the number buyers ask for. Construction is the one that decides whether the towel still has loft at the end of the season.
GSM is grams per square metre: how much cotton is in the towel. It is the first number on every quotation, and it is useful, but on its own it says less about how a towel performs than buyers expect.
Weight is where the comparison starts
Below 450 GSM a bath towel reads as light; between 500 and 600 it reads as hotel standard; above 600 it reads as plush. That is the feel in the hand on the first day.
Construction decides how it ages
Two towels at the same weight can behave very differently after fifty commercial washes. Pile height, the twist of the yarn and the strength of the ground weave decide whether the loops stay upright or flatten.
A heavy towel with a weak ground weave sheds. A lighter one with a tight ground weave lasts.
Ask for the construction alongside the weight, and test both in your own laundry before the order is placed.
