Overview
ISO 11859:1999 specifies requirements for pure wool, hand-knotted pile carpets where dimensions are agreed between purchaser and supplier. Prepared by ISO/TC 38 (Textiles) SC 12 (Textile floor coverings), the standard prioritizes non-destructive testing where possible and includes two normative annexes for measuring knots and for calculating theoretical pile density.
The standard is intended for manufacturers, suppliers, purchasers and testing laboratories involved in quality control, acceptance testing and product marking of hand-knotted carpets.
Key Topics
- Material content: Pile yarn shall be 100% wool, with limited allowances for non-wool fibres only for decorative purposes (up to 0.3% or up to 5% if clearly distinguishable).
- Dimensional tolerances: Tolerances on total length and width are specified by carpet width (e.g., ±2% for widths up to 2 m; ±1.5% for widths over 2 m). Pile height (or tuft leg length) tolerance is nominal ±1 mm.
- Knots and density: Tolerance on number of knots per metre is nominal ±5%. The standard requires a minimum theoretical pile density value (listed in the standard and determined per Annex B).
- Colour fastness and durability: Specified minimum grades include colour fastness to artificial light (ISO 105-B02), rubbing (dry) and to water (ISO 105-E01), with threshold values given in the standard.
- Non-destructive approach: The introduction emphasizes using non-destructive test methods where feasible to preserve valuable hand-knotted carpets.
- Marking requirements: Each carpet label must include the ISO reference (ISO 11859:1999), manufacturer/supplier identity, carpet dimensions, surface fibre type and content, pile height (mm), knots per square metre, pile yarn mass per mm of pile height (g/m2), and cleaning/maintenance instructions.
Applications
- Quality assurance and incoming inspection for pure wool hand-knotted carpets supplied to commercial and residential projects.
- Contract specification for buyers and suppliers to ensure agreed dimensions, pile characteristics and colourfastness.
- Laboratory testing protocols and reporting where standard atmosphere may not be available (the standard permits near-standard conditions provided they are recorded).
Related Standards
Normative references cited in ISO 11859:1999 include:
Practical value: ISO 11859:1999 provides a concise specification framework that helps align manufacturer practices, testing methods and purchaser expectations for authentic pure wool, hand-knotted pile carpets.