Grammage

Grammage is a key physical indicator for sheet materials such as paper, paperboard, non-woven fabrics, and films. It refers to the weight per square meter of material, expressed in grams per square meter (g/㎡ or gsm). In foreign trade, grammage directly determines material thickness, strength, feel, and price, and is a core specification parameter in contracts, letters of credit, and quality inspection reports. Usage scenarios include procurement and sales in industries such as paper, packaging materials, textiles, and hygiene products. Precautions: Different countries may use different units (e.g., lb/ream in the US), requiring conversion; grammage is different from thickness (Caliper), as thickness is affected by density; the allowable tolerance for grammage is usually ±5%, which must be specified in the contract; grammage affects freight and tariff classification. It is synonymous with 'substance weight,' but 'grammage' is more commonly used in spoken language and trade practice. Difference from 'Basis Weight': basis weight is the weight under a specific number of sheets, while grammage is an internationally standardized indicator. Foreign trade practitioners should accurately understand grammage to avoid claims caused by specification non-compliance.