The paper density of a type of paper or cardboard is the collection of the product per unit of area. Two ways of expressing paper density are usually used:
* Expressed in grams per square metre (g/m²), paper density is also called as grammage. This is the evaluate used in most parts of the world.
* Expressed in conditions of the mass (in pounds) of a ream of 500 (or in some cases 1000) sheets of a specified (raw, still uncut) basis size, paper density is called as basis weight. The base size and area used here based on the product type. This convention is used in the