gramatury

Gramatura, also known as grammatura or grammage, is the mass per unit area of a sheet, most commonly used for paper and cardboard. It is expressed in grams per square meter (gsm or g/m^2) and provides a size-independent way to compare the “heaviness” or density of sheets. Unlike US weight measures that refer to a nominal mass per sheet at a specific size, grammage describes the material’s intrinsic mass per area.

Measurement and standards: Gramatura is determined by weighing a precisely cut sample of known area, typically conditioned under standard temperature and humidity. The procedure is standardized in methods such as ISO 536 for paper and board. The reported grammage reflects density and fiber content, but moisture content and surface coatings can influence the result.

Typical ranges and implications: Writing and printing papers commonly range from about 60 to 120 gsm, with office paper usually around 80–90 gsm. Text papers often sit in the 90–120 gsm range. Cover stock and cards range roughly 200–300 gsm, while cardboard and packaging materials can be significantly heavier, sometimes exceeding 600 gsm for thick boards. In general, higher gramatura increases stiffness, opacity, and durability, but raises cost, weight, and may alter ink handling and absorbency.

Practical notes: Gramatura is a central specification when selecting paper for printing, binding, or packaging. In some markets, gramatura is used interchangeably with grammage, while in others, basis weight expressed in pounds per ream serves as the practical alternative for certain standard sizes. Temperature, humidity, and coatings should be considered when comparing grammage across products.