Overview
ISO 7211-2:1984 - Textiles - Woven fabrics - Construction - Methods of analysis - Part 2: Determination of number of threads per unit length - defines three accepted laboratory methods for measuring thread count (threads per centimetre) in woven fabrics. The standard explains how to determine warp ends per centimetre and weft picks per centimetre, how to calculate threads per square centimetre, and when each method is appropriate based on fabric character.
Key topics and requirements
- Three measurement methods
- Method A - Dissection (recommended in disputes): physically dissect a fabric section and count threads over a defined measuring distance. Requires test pieces containing at least 100 threads and counting at multiple points to represent the fabric.
- Method B - Counting glass: visually count threads through an aperture of a specified counting glass placed on the fabric; suitable for many woven fabrics where threads are visible.
- Method C - Traversing thread counter: use a low‑power microscope mounted on a traversing stage (screw‑driven) to count threads across a graduated base; suitable for a wide range of fabrics.
- Preparation and atmosphere
- Test specimens must be conditioned in a standard atmosphere for testing textiles (see ISO 139) and exposed for at least 16 hours prior to measurement.
- Result expression and calculation
- Report ends per centimetre (warp) and picks per centimetre (weft); threads per square centimetre = sum of mean ends and picks per cm.
- For fabrics with low thread counts, results may be expressed per decimetre; for narrow fabrics report threads per full width.
- Annex (informative)
- Parallel-line and taper-line gratings are described for quick estimates (not recommended as primary standard methods).
Practical applications and users
ISO 7211-2 is used in:
- Textile mills and fabric manufacturers for incoming/outgoing quality control and specification compliance.
- Independent textile testing laboratories for standardized thread‑count reporting.
- Garment and upholstery producers verifying fabric construction for performance and appearance.
- R&D and textile engineering for weave analysis and development of new fabrics.
- Standards organizations and procurement teams specifying textile acceptance criteria.
Benefits include consistent, repeatable thread-count results, clear guidance on method selection for different fabric types, and standardized reporting of ends/picks and area thread density.
Related standards
- ISO 139 - Textiles - Standard atmospheres for conditioning and testing (referenced for conditioning requirements).
- Annex methods in ISO 7211-2 provide supplementary estimation techniques but are explicitly described as less accurate for formal testing.
Keywords: ISO 7211-2, thread count, threads per centimetre, woven fabrics, counting glass, traversing thread counter, dissection method, textile testing, ends per cm, picks per cm.
Open preview (PDF)Textiles — Woven fabrics — Construction — Methods of analysis — Part 2: Determination of number of threads per unit length
