Grammages

Grammages refers to the mass per unit area of a sheet or sheet-like material, most commonly paper. It is measured in grams per square meter (gsm) and expresses the material’s density, thickness, and general feel. Grammage is an intrinsic property: cutting a sheet into smaller pieces does not change its grammage; the total mass scales with area, while the area is constant.

Grammage is typically determined by weighing a sample of known area and calculating mass per square meter. In practice, manufacturers specify grammage rather than basis weight, especially outside North America, though both describe weight per area. The concept is widely used across paper, cardboard, and other sheet materials.

In paper and boards, grammage influences handling properties such as stiffness, opacity, printability, and perceived quality. Lighter papers (e.g., about 60–90 gsm) are common for newsprint and lightweight office uses; mid-range (80–160 gsm) for general office papers and flyers; heavier boards (200–600 gsm) for packaging and covers. Textile fabrics and other sheet-like materials often report weight per area in gsm as well, affecting drape and durability.

Choosing grammage depends on intended use, printing method, and finishing. Higher grammage generally yields stronger, less translucent stock but can increase cost and rigidity. Finishes, coatings, and fiber content can alter the feel and performance beyond the base grammage.

The term derives from French and is widely used in Europe and parts of Asia to describe material weight by area, in contrast to the U.S. system of basis weight expressed in pounds per ream.