Overview
EN ISO 11640:2018 - Leather: Colour fastness to cycles of to-and-fro rubbing specifies a standardized method for assessing how a leather surface behaves when rubbed with a wool felt (the VESLIC rub test). It is applicable to all kinds of leather and defines apparatus, test specimens, conditioning, procedure and assessment criteria to evaluate transfer (staining) and change in colour caused by repeated to-and-fro rubbing.
Key Topics
- Test principle: A leather specimen is rubbed with reference wool felt under a defined pressure for a given number of forward and backward cycles. Results are evaluated for staining of the felt and change in the leather colour using grey scales or instrumental measurement.
- Apparatus requirements:
- Rub fastness machine with a planar platform and carriage (35–40 mm travel) driven at about 40 cycles/min ±2.
- A removable finger assembly with 15 mm × 15 mm base and a loading arrangement producing a total mass ~1 000 g ±35 g (finger mass 500 g ±25 g, plus weight-piece).
- Reference rubbing material:
- Square wool felt pieces ~15 mm × 15 mm, thickness 6.0 mm ±0.5 mm, mass per unit area ~1 900 g/m² ±150 g/m²; white or black felt (black dyed with Acid Black 24 or equivalent).
- Conditioning and wetting:
- Procedures for dry/wet leather and felt conditioning per ISO leather conditioning practices; wetting methods include boiling/soaking or vacuum wetting (~5 kPa).
- Option to use felt wetted with artificial perspiration solution.
- Assessment:
- Visual grey scales (ISO 105‑A02 and ISO 105‑A03) or instrumental methods (ISO 105‑A04 / A05) to rate change in colour and staining; report any surface damage.
- Precision and reporting: The standard includes guidance on specimen size, sampling (ISO 2418), conditioning (ISO 2419), and the test report content.
Applications
- Quality control for tanneries, leather finishers and suppliers to verify rub fastness and dye transfer performance.
- Product testing for footwear, upholstery, automotive interiors, leather garments and accessories to predict in‑use abrasion and staining risks.
- Contract/specification compliance testing for brands, retailers and independent testing laboratories.
- Comparative testing during formulation of dyes, finishes and topcoats to improve colour fastness to rubbing.
Who Uses This Standard
- Leather manufacturers, quality assurance engineers and laboratory technicians
- Independent materials testing laboratories and certification bodies
- Product designers, specifiers and procurement teams in footwear, furniture and automotive industries
- R&D teams developing leather treatments, dyes and protective finishes
Related Standards (select)
- ISO 105‑A01 / A02 / A03 / A04 / A05 (colour fastness assessment)
- ISO 2418, ISO 2419 (sampling and conditioning)
- ISO 11641 (perspiration fastness)
- EN 15987 (leather terminology)
Keywords: EN ISO 11640:2018, colour fastness, leather rubbing, VESLIC rub test, wool felt, rub fastness apparatus, grey scale, leather testing.
