Overview
ISO 12625-6:2016 specifies a standardized test method for the determination of grammage of tissue paper and tissue products. Published as the second edition (2016), this ISO test standard defines the principle, apparatus, sampling, conditioning, preparation, measurement and calculation procedures needed to report grammage (mass per unit area, expressed in g/m²) reliably and reproducibly.
Key Topics
- Scope and principle
- Defines grammage as the mass of a unit area of tissue paper or tissue product measured according to the method.
- Grammage is determined from measured mass and area of test pieces or finished items.
- Apparatus and accuracy
- Requirements for cutting devices (repeatable cuts, area accuracy within ±1.0%), balances (measuring accuracy 0.001 g), and length/area measurement devices (minimum accuracy 0.5 mm).
- Sampling and conditioning
- Sampling for lot evaluation should follow ISO 186; conditioning of samples must follow ISO 187 and remain in the standard atmosphere throughout testing.
- Preparation and test-piece requirements
- Test pieces must be free from creases and defects.
- Minimum individual test-piece area: 100 cm²; minimum total tested area: 1 000 cm².
- Minimum number of test pieces: 10 (random selection guidance for finished products).
- Measurement procedure
- Mass to nearest 0.001 g; area measured with suitable device or scanner while items lie flat.
- Option to weigh pieces individually or together (note: weighing together prevents calculation of standard deviation).
- Calculation and reporting
- Grammage calculated as mass per unit area and expressed to three significant figures; mean and sample standard deviation calculated per Clause 10.
- Test report must reference ISO 12625-6, give sample identification, numerics (grammage, standard deviation, coefficient of variation), conditioning atmosphere and any deviations from the method.
Applications
ISO 12625-6 is used by:
- Tissue manufacturers and converters for quality control and specification verification.
- Test laboratories performing contract or regulatory testing of tissue products.
- Product development teams validating product weight targets, material usage and cost control.
- Procurement and QA teams requiring consistent grammage data for supplier comparisons.
Keywords: ISO 12625-6, tissue paper grammage, tissue products, grammage test method, tissue testing standard, ISO tissue paper.
Related Standards
- ISO 186 - Sampling to determine average quality (referenced for lot sampling)
- ISO 187 - Standard atmosphere for conditioning and testing (referenced for conditioning)