Gramajes

Gramajes, or grammage, is the mass per unit area of a material, commonly expressed as grams per square meter (g/m^2 or gsm). It is used primarily in the paper and textile industries to describe how heavy or dense a sheet or fabric is. In paper, grammage helps determine suitability for printing, packaging, and coating, as it influences stiffness, opacity, durability, and print quality.

Measurement and standards: Grammage is determined by cutting a specimen to a defined area, conditioning it under standard environmental conditions, weighing it with a precise balance, and calculating mass per unit area. In paper and board, ISO 536 is a standard method for this measurement. In textiles, the analogous procedure is often described as fabric mass per unit area, with methods such as ASTM D3776 and ISO equivalents used in many markets. Typical ranges vary widely: writing or copy paper is commonly around several tens to around a hundred gsm, heavier coated papers and cover stock are greater, and cardboard can exceed two hundred gsm.

Textiles and other materials: For fabrics, gsm values indicate weight and can affect drape, warmth, and durability. Lightweight fabrics may be under 100 gsm, midweights range 120–250 gsm, and heavy fabrics, such as denim, can reach 350–500 gsm or more.

Relation to thickness: Grammage does not uniquely determine thickness; density or caliper also play a role. Two sheets with the same gsm may have different thicknesses depending on material structure, coatings, and compaction.

Applications and terminology: The term gramaje is widely used in Spanish-speaking contexts, while grammage is common in English. The concept is essential for material specification, cost estimation, and quality control across printing, packaging, and textile industries.