ISO 11641:2025

Overview

ISO 11641:2025 - Leather - Tests for colour fastness - Colour fastness to perspiration is an international test method for assessing how leather colours resist exposure to human perspiration. Prepared by IULTCS and ISO, this third edition defines a reproducible laboratory procedure that simulates alkaline (and optionally acid) perspiration and measures both colour change of the leather and staining of adjacent fabrics.

Keywords: ISO 11641:2025, colour fastness to perspiration, leather testing, artificial perspiration, leather quality control

Key topics and technical requirements

• Scope: Applies to leather of all kinds at all stages of processing, with particular relevance to gloving, clothing, lining leathers and uppers of unlined shoes.
• Principle: Leather test pieces are soaked or wetted with an artificial perspiration solution, pressed against specified adjacent fabric(s) and held under controlled pressure and temperature; after drying the leather and adjacent fabrics are evaluated for colour change and staining.
• Artificial perspiration: Primary test uses an alkaline solution adjusted to pH 8.0 ± 0.1. Composition per litre includes NaCl, tris(hydroxymethyl)aminomethane, urea and nitrilotriacetic acid. An acid perspiration alternative (pH 5.5 ± 0.1) is also referenced.
• Apparatus & conditions: Test assembly uses a stainless-steel frame and a weight-piece (~5 kg) to apply a uniform pressure of 12.5 ± 1.0 kPa; oven temperature is 37 °C ± 2 °C. Vacuum treatment and controlled immersion procedures are specified.
• Evaluation: Use ISO grey scales for assessing change in colour and staining (ISO 105-A02 / A03) or instrumental assessment (spectrophotometer/colorimeter) per ISO 105-A04/A05.
• Specimen preparation: Options for testing leather with finish intact or with finish broken (abrasion step described), and guidance on sample sizes and adjacent fabrics (multifibre or single-fibre).

Practical applications and users

• Who uses it: Leather manufacturers, footwear and glove producers, textile/leather testing laboratories, quality assurance teams, product developers and compliance officers.
• Why use it: To validate colour stability under realistic wear conditions, support supplier acceptance criteria, assist in troubleshooting dyeing/finishing problems, and ensure product performance for garments, gloves and shoe uppers.
• Benefits: Provides reproducible, industry-recognised results that inform formulation, finishing choices and consumer safety/appearance expectations.

Related standards

• ISO 7906 - General principles of colour fastness testing for leather
• ISO 2418 - Specimen position and preparation for leather tests
• ISO 105 series (A02, A03, A04, A05, E04, F01–F10) - Grey scales, staining and adjacent fabric specifications
• ISO 3696 - Water for analytical laboratory use

This standard is indispensable for consistent, comparable assessment of leather colour fastness to perspiration and for maintaining product quality across the leather supply chain.