property>mass per unit area
What is Mass Per Unit Area?
As a physical property, mass per unit area is a simple concept with many applications. It can simply be another way of expressing a material density for a fixed thickness, or the mass for a unit area of a composite material. It can also refer to the mass of a substance applied to a given area, for example a covering material such as paint, or in agriculture to the mass of fertilizer or other material applied per unit area of land, or the crop yield (by mass).
Often the mass per unit area is a property used for practical reasons. For example, carpet is usually measured by area, so in order to be able to know the weight of a given quantity of carpet (for shipping), the manufacturer will need to quote a mass per unit area in their specifications.