Overview
EN ISO 12625-15:2022 - Tissue paper and tissue products - Part 15 - specifies instrumental test methods for the determination of brightness and colour of tissue paper and tissue products under C/2° (indoor daylight) viewing conditions. Prepared by ISO/TC 6 in collaboration with CEN, this 2022 edition updates the 2015 version and defines procedures for sampling, conditioning, preparation of test pieces (single‑ply and multi‑ply), measurement, calculation and reporting of optical properties. Note: results differ from D65/outdoor daylight methods because of different UV content and measurement conditions.
Key topics and requirements
- Scope and purpose: Instrumental determination of brightness and colour for tissue products viewed in indoor daylight (C/2°).
- Measurement conditions: C/2° geometry (indoor daylight illuminant with 2° observer conditions) as the reference measurement environment.
- Preparation of test pieces: Instructions for single‑ply and multi‑ply products and precautions where product texture or opacity affects readings.
- Apparatus and calibration: Requirements for appropriate spectrophotometers/reflectometers, calibration routines and reference standards to ensure traceable optical measurements.
- Sampling and conditioning: Sampling to determine average quality (ISO 186) and conditioning in a standard atmosphere (ISO 187) before testing.
- Test procedure: Step‑by‑step measurement for ISO brightness (diffuse blue reflectance) and colour values (CIE Lab* under C/2°), including calculation of single values, means and dispersion.
- Reporting and precision: Required test report content and precision information (Annex A) to support reproducibility and quality control.
Applications and who uses this standard
- Tissue manufacturers use EN ISO 12625-15:2022 for production control, product specification and batch acceptance.
- Quality control and analytical laboratories apply the method to certify brightness and colour under indoor daylight conditions.
- Product development and R&D teams evaluate optical appearance, whitening agents and optical brightening effects in prototype materials.
- Procurement and compliance professionals reference the standard in specifications and supplier contracts to ensure consistent visual performance.
- Certification bodies and standards committees use the method as a basis for conformity assessment and comparative testing.
Related standards
This standard is essential for anyone specifying, testing or comparing the visual appearance of tissue paper and tissue products under indoor daylight conditions. Keywords: EN ISO 12625-15:2022, tissue paper, brightness, colour measurement, C/2°, indoor daylight, ISO brightness, optical properties, testing procedures.
