gramatura

Gramatura is the measure of weight per unit area of a material, expressed in grams per square meter (g/m^2). The term is used primarily in European textile and paper industries and serves as a straightforward indicator of density or heaviness. In textiles, grammage describes how heavy or dense a fabric is and relates to properties such as opacity, warmth, and durability, though fiber content, weave, and finishes also influence performance. In paper, grammage indicates sheet weight and is a primary quality parameter for printability and rigidity.

Measurement of grammage involves conditioning a sample in standard atmosphere, cutting a piece of known area (commonly around 10 cm by 10 cm), weighing it with a precision balance, and calculating grammage as mass divided by area. The result is expressed in g/m^2; for a sample with area 0.01 m^2, grammage equals the measured mass in grams multiplied by 100.

Typical ranges vary by material. Textile grammages vary with purpose: lightweight fabrics may be under 100 g/m^2; midweight fabrics commonly range from about 100 to 250 g/m^2; heavyweight fabrics exceed roughly 250 g/m^2. Paper grammage covers a broad spectrum: office papers usually around 80–100 g/m^2, copier papers about 70–90 g/m^2, card stocks from roughly 200–350 g/m^2, and packaging papers well above 200 g/m^2.

Limitations: Grammage is a convenient standardized indicator of weight per area but does not alone determine performance; factors such as fiber or material composition, finish, density, and processing all influence handling, drape, opacity, and durability.