🧵 Determination of the number of warp and weft threads per centimetre in woven fabrics by three methods — A: dissection of a specimen of the measuring distance and counting of the removed threads (all fabrics, takes precedence in dispute), B: counting threads in the aperture of a counting glass (fabrics above 50 threads/cm), C: traversing thread counter (all fabrics) — minimum measuring distances by density (Table 1), at least five counting places, conditioning according to ISO 139, PN-EN ISO 7211-2

Materials and NDT PN-EN ISO 7211-2

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in two iTeh samples: SIST EN ISO 7211-2:2024 (English text) — title page, contents and European foreword — and ISO 7211-2:2024 (English text) — from the title page through the contents, foreword and Clauses 1–7 to 8.1 (apparatus of method A) on page 2 inclusive. Outside the samples remain the procedure of method A (8.2), methods B and C with apparatus and procedures (Clauses 9 and 10), calculation and expression of results (11) and the test report (12).

ACCORDING TO THE TEXT OF ISO 7211-2:2024 (forewords, Clauses 1–8.1). The standard was prepared by ISO/TC 38/SC 24 in collaboration with CEN/TC 248 “Textiles and textile products” (secretariat BSI) under the Vienna Agreement; CEN approved EN ISO 7211-2 on 03.09.2024 without modification from ISO; EN ISO 7211-2:2024 superseded EN 1049-2:1993, and the second ISO edition (2024-08) — ISO 7211-2:1984; main changes: in Clause 5 two columns of the former table were deleted, in Clause 12 mandatory report items were added, the annex was deleted. Scope (1): three methods for the determination of the number of threads per centimetre in woven fabrics; any can be used, the choice depending on the character of the fabric, but in case of dispute method A takes precedence. Method A — dissection of fabric, suitable for all fabrics, the most laborious but with fewer limitations, the only one really suitable for certain folded structures and other complicated weaves; method B — counting glass, for fabrics with more than 50 threads per centimetre; method C — traversing thread counter, for all fabrics. Where the number of threads per centimetre is low, results can be expressed per decimetre. Normative reference (2): ISO 139 (standard atmospheres for conditioning and testing). No terms are defined (3). Principle (4): in method A a section of fabric of dimensions according to Clause 5 is dissected and the threads counted; the threads to be counted are preferably short, 10 mm or 20 mm being suitable; in method B the threads visible within the aperture of a counting glass are counted; in method C the number of threads per centimetre is determined with a traversing thread counter. Minimum measuring distance (5, Table 1): fewer than 10 threads/cm — 10 cm, 10–25 threads/cm — 5 cm, 25–40 — 3 cm, more than 40 — 2 cm; in method A specimens contain at least 100 threads; for narrow fabrics up to 10 cm wide all warp threads including selvedge ends are counted and the result is expressed per full width; for patterned fabrics with areas of large differences in density the specimen contains at least one weave repeat. Conditioning (6): atmosphere according to ISO 139. Specimens (7): not from within 150 mm of either edge of the laboratory sample; except for method A no specially prepared specimens are required; threads are counted in at least five different places so that they do not contain the same ends and picks and represent the fabric as fully as possible; the count is based on the threads actually present; the fabric or specimens are conditioned in the standard atmosphere for at least 16 h before testing in a tension-free state. Apparatus of method A (8.1): a clamp holding two short pins parallel, their points within ±0,2 mm of the measuring distance, or — without a clamp — two dissecting needles, a heavy steel rule graduated at 0,5 mm and pointed forceps.

STATUS (as of 03.10.2026). The PKN search (term “PN-EN ISO 7211-2”, 03.10.2026) shows one item: PN-EN ISO 7211-2:2025-03 (English version, “Introduces: EN ISO 7211-2:2024 [IDT], ISO 7211-2:2024 [IDT]”) without a withdrawal note. The term “PN-EN 1049-2” gives PN-EN 1049-2:2000 (Polish version, “Introduces: EN 1049-2:1993 [IDT], ISO 7211-2:1984 [MOD]”) with the note “Withdrawn and replaced by PN-EN ISO 7211-2:2025-03”. In the iTeh catalogue (read on 03.10.2026) EN ISO 7211-2:2024 and ISO 7211-2:2024 have the status “Published” (stage 60.60, 04.09.2024 and 22.08.2024 respectively).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 03.10.2026). The number 7211-2 appears in 6 records at 5 laboratories: AB 154, AB 164 (2), AB 198, AB 1417, AB 1421. In the current PCA documents (read on 03.10.2026, issues from 29.12.2025 to 08.07.2026) the number appears in 6 rows of the same laboratories (AB 164 — 2, at two locations, the others 1 each); in none of the five documents are page numbers repeated. Everywhere the form “PN-EN ISO 7211-2:2025-03”, at AB 1421 with the addition “p.8” (method A); at AB 154, AB 164 and AB 1417 the withdrawn PN-EN 1049-2:2000 also stands in the same row (at AB 1417 “p. 7”). None of these items is suspended. The “Laboratories” tab (term “PN-EN ISO 7211-2”) shows 4 laboratories: AB 154, AB 164, AB 198 and AB 1421; AB 1417 is under “PN-EN 1049-2”, because that designation stands first there — checked with tab queries on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Woven fabrics (AB 164, AB 198), textiles, woven fabrics, clothing (AB 1417), flat textile products (AB 154; at AB 1421 woven and knitted fabrics). Characteristics: number of warp and weft threads per unit length (AB 154, AB 198, AB 1417), warp and weft count per 1 cm (AB 164, AB 1421), number of threads per cm² “calculated” (AB 164, AB 1417, AB 1421). Method A is entered at AB 198, AB 1417 (“pulling threads out of the product”) and AB 1421; at AB 154 and AB 164 without indication of the method. The number of threads per cm² is not defined by the standard in the part we read — it is a quantity calculated by the laboratories.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. With the choice of method: B only for fabrics above 50 threads/cm; in dispute A decides; for complicated weaves only A is really suitable (1). With the distance: too short a distance for an open fabric — from 10 cm below 10 threads/cm to 2 cm above 40 (5, Table 1); in method A at least 100 threads. With sampling: not closer than 150 mm to the edge, at least five places without common threads (7). With patterned fabrics: the specimen includes at least one weave repeat (5). With narrow fabrics up to 10 cm: all warp threads including selvedge ends, result per full width (5). With conditioning: at least 16 h in the ISO 139 atmosphere, tension-free (6, 7). With the reference: PN-EN 1049-2:2000 is withdrawn, and many scopes cite it alongside its successor.

WHAT WE DO NOT GIVE. We did not read the course of dissection in method A, the design of the counting glass and the traversing counter, the procedures of methods B and C, the method of calculating and rounding the result or the report items (8.2, Clauses 9–12).

Method principle

The number of warp and weft threads per centimetre is determined over a measuring distance whose minimum length depends on the fabric density (from 10 cm to 2 cm). In method A a specimen of this dimension is dissected and the removed threads counted, in method B the threads visible in the aperture of a counting glass are counted, in method C — with a traversing counter. Counting is done in at least five places of the conditioned fabric, away from the edges, and in dispute method A decides.

Applications

• Woven fabrics of all kinds — methods A and C; fabrics above 50 threads/cm — method B (1)
• Complicated weaves and folded structures — method A (1)
• Woven fabrics, textiles, clothing, flat textile products — warp and weft count in the accreditation scopes of 5 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN ISO 7211-2:2025-03

Title (PL)

Tekstylia — Metody analizy struktury wyrobów tkanych — Część 2: Wyznaczanie liczby nitek na jednostkę długości

Title (EN)

Textiles — Methods for analysis of woven fabrics construction — Part 2: Determination of number of threads per unit length

Step-by-step procedure

1. Conditioning

   Fabric or specimens at least 16 h in the atmosphere according to ISO 139, tension-free (6, 7). PN-EN ISO 7211-2:2025-03 without a withdrawal note (03.10.2026).

2. Choice of method and distance

   Method according to the character of the fabric (A, B, C); minimum distance according to Table 1 (1, 5).

3. Counting places

   At least five places, not closer than 150 mm to the edge, without common threads; in patterned fabrics at least one weave repeat (5, 7).

4. Counting

   Method A — dissection of the specimen and counting of removed threads (at least 100); B — in the aperture of the counting glass; C — with the traversing counter (4).

5. Result

   Warp and weft threads per centimetre, at low density per decimetre; calculation according to Clause 11 (not read).

Required equipment and apparatus

Health and safety (OHS)

• Dissecting needles and pointed forceps — risk of puncture

Frequently asked questions