Basis weight
The mass of a nonwoven per unit area, stated in grams per square metre.
Basis weight (GSM)
Basis weight is the first number on any data sheet and the one most often compared in isolation. It sets the amount of fibre in the web, and therefore the absorption capacity and much of the cost, but it says nothing about how the fibre is arranged. Two webs at the same basis weight can feel and perform differently if the blend or the entanglement differs.
In a quotation it should be stated as a nominal value with a tolerance, because a web is produced within a range rather than at an exact figure.