Overview
ISO 11642:2025 - Leather - Tests for colour fastness - Colour fastness to water specifies a laboratory method to determine colour fastness to water of leather of all kinds at all stages of processing. Prepared by IULTCS/IUF and updated in 2025, the standard defines the principle, apparatus, test pieces, procedure, evaluation and reporting requirements for reproducible leather water fastness testing.
Key topics and technical requirements
- Scope: Applies to leather (finished or unfinished) at any processing stage; finishes may be tested intact or with the finish broken.
- Test principle: A leather test piece and pre-wetted adjacent fabric are pressed together under a defined pressure, held at controlled temperature, dried and then assessed for colour change and staining.
- Critical test parameters:
- Pressure: 12.5 ± 1.0 kPa applied by a stainless-steel frame and ~5 kg weight-piece.
- Temperature: 37 °C ± 2 °C (oven).
- Duration: 180 min ± 10 min under load.
- Vacuum pretreatment: immersion in demineralized water (ISO 3696 grade 3) with evacuation to ~5 kPa (repeat cycles).
- Apparatus & materials: Perspirometer-type apparatus (examples listed in Annex A), glass/acrylic plates, adjacent fabrics (multifibre ISO 105‑F10 or single-fibre ISO 105‑F01–F07), P180 abrasive paper for breaking finishes, grey scales (ISO 105‑A02/A03) and optional instrumental assessment (ISO 105‑A04/A05 spectrophotometer/colorimeter).
- Evaluation: Visual assessment using grey scales under D65 illumination (ISO 7906) or instrumental measurement when staining and colour change are even. Typical inter-person precision: ±0.5 grey scale units.
- Reporting: Test report must reference ISO 11642:2025 and include leather type, side tested, finish status, adjacent fabric used, grey scale ratings for staining and colour change, deviations, observations and test date.
Applications and users
ISO 11642:2025 is used for quality control, product development and compliance in industries that work with leather, including:
- Leather manufacturers and tanneries
- Footwear, upholstery and automotive leather suppliers
- Laboratory and independent testing services
- R&D and quality-assurance teams evaluating dye stability, finishing processes and material acceptance criteria
Benefits include consistent assessment of water-induced colour transfer, objective comparison between batches, and evidence for product specifications and claims.
Related standards
- ISO 7906 - General principles of colour fastness testing (leather)
- ISO 2418 - Specimen position and preparation for leather testing
- ISO 3696 - Water for analytical laboratory use
- ISO 105 series (A02, A03, A04, A05, F01–F10) - Grey scales, staining assessment and adjacent fabric specifications
Keywords: ISO 11642:2025, colour fastness to water, leather testing, fastness tests, adjacent fabric, grey scale, perspirometer, leather quality control.
