What is GSM? Rebecca Leonard September 29, 2019 08:43 Updated Follow GSM is an abbreviation for "grammes per square metre" and indicates how heavy a fabric is. When talking about towels, a higher GSM indicates a denser and fluffier towel that's more absorbent. Related articles Is it better to have a higher GSM? What is the purpose/benefit of a Hammam Towel? Which one of our towels is the heaviest? What is the softest towel in our range? What size is a Bath Towel? Comments 0 comments Please sign in to leave a comment.