Overview
ISO 15700:1998 specifies a standardized laboratory method for assessing colour fastness to water spotting of leather. Prepared by the IULTCS Fastness Tests Commission (IUF 420), the standard describes how to evaluate both the physical effects (swelling, loss of lustre) and the colour change caused when droplets of water contact leather surfaces. The method is suitable for all kinds of leather and includes an alternative procedure for patent and plastic‑coated leathers.
Key topics and requirements
- Test principle: Two drops of distilled water are applied to the leather surface; one drop is blotted after 30 minutes and observed for physical effects, the other is allowed to evaporate (about 16 hours) and the colour change is rated.
- Volume and spacing: Drops of approximately 0.15 ml, placed about 50 mm apart.
- Water quality: Use distilled water meeting ISO 3696 (grade 3).
- Assessment of colour change: Visual assessment using the grey scale (ISO 105‑A02) or instrumental assessment per ISO 105‑A05.
- Physical effects: Record observable effects (e.g., swelling, loss of lustre) and describe severity as slight, moderate, or severe.
- Special procedure for patent/plastic‑coated leather: Wet the inside surface until water penetrates or causes swelling, then assess effects after 30 minutes.
- Optional simulated wear: Pieces may be pre‑treated (e.g., repeated flexing) to assess the effect of wear on water‑spotting resistance.
- Reporting: Test report must reference ISO 15700 and include leather type, surface tested, physical effects and severity, grey scale ratings (before/after manual treatment and wear if applicable), deviations from procedure, and test date.
Applications and users
ISO 15700 is used to:
- Verify quality and performance of finished leathers for footwear, upholstery, clothing, and gloves.
- Support production quality control in tanneries and leather finishing operations.
- Evaluate finished leather batches for resistance to water spotting during end‑use (e.g., shoe uppers, furniture, garments).
- Inform product development and comparative testing by leather chemists and R&D teams.
Primary users include leather manufacturers, quality control laboratories, footwear and furniture makers, material specifiers, and independent testing labs.
Related standards
- ISO 105‑A01 - General principles of colour‑fastness testing (textiles)
- ISO 105‑A02 - Grey scale for assessing change in colour
- ISO 105‑A05 - Instrumental assessment of colour change
- ISO 3696 - Water for analytical laboratory use
- IUF 420 / IULTCS methods - historical basis and related leather colour fastness guidance
Keywords: ISO 15700, leather, colour fastness, water spotting, grey scale, IULTCS, IUF 420, distilled water, patent leather, leather testing.