ISO 7211-6:2020 Textiles — Methods for analysis of woven fabrics construction — Part 6: Determination of the mass of warp and weft per unit area of fabric.
5.3 DissectIon needle.
5.4 Small template. Template to mark (or a die to cut) a square or a rectangle of known area of not less than 150 cm2. The length to width ratio of the rectangle shall not exceed 4.
5.5 Large template. Template to mark (or a die to cut) a square which is sufficiently large to enclose the area marked with the smaller template (&4) when placed with its diagonals parallel to the sides of the enclosed square or rectangle.
5.6 Balance, accurate to 0,1 % of the smallest quantity to be weighed.
6 Conditioning and testing atmosphere
The standard atmospheres for pre-conditioning, conditioning and testing textiles specified in ISO 139 shall be used.
7 Test specimens
7.1 Conditioning
Before marking or cutting, expose the samples from which the test specimens will be removed to the standard atmosphere for conditioning until it is in equilibrium with that atmosphere.
Take the specimens from each sample.
7.2 Method A
With the aid of the large template (5S), mark in pencil on the sample a square with its diagonals in the direction of the warp and welt threads. In the centre of the square, and with the aid of the small template (SA), mark in indelible ink (Sd) a square or rectangle with its sides in the directions of the warp and weft threads. Cut the larger square from the sample by means of the scissors (5.2) and identify the warp and welt directions. Alternatively, remove the larger square from the sample by means of a die.
When the amount of non-fibrous matter has not to be determined, the larger specimen may be of any shape or size, provided that the threads are retained in the inner marked area during the removal of added matter.
7.3 Method B
With the aid of the small template (SA), mark in pencil a square or a rectangle with its sides as closely as possible parallel to the warp and welt threads. Cut the square or rectangle from the fabric by means of the scissors (52) and identify the warp and weft directions. Alternatively, remove a square of the appropriate size from the fabric by means of a die.
8 Procedure
8.1 Method A
Remove any non-fibrous matter from the sample according to one of the methods described in ISO 1833-1. Expose the sample to the atmosphere for conditioning and testing until equilibrium is attained.
Cut along the sides of the inner square or rectangle which was marked on the sample before the removal of added matter. ISO 7211-6 pdf download.