textiles The measurement of yarn size is essentially on the basis of mass to length, this being termed a ‘yarn count’. Traditional units have mostly been of length to unit mass; hence the larger the number the thinner the yarn (so measures of thinness); while thinner yarns are usually seen as superior, measurement on this basis was effectively indirect, taking the reciprocal from a weighing of a fixed length. Such an approach has been largely discarded in favour of one directly expressing mass to unit length (measures of thickness), the familiar denier being such a unit, the less familiar tex being now the standard.
[ISO 2947:1973 Textiles - Integrated Conversion Tables for Replacing Traditional Yarn Numbers by Rounded Values in the Tex System] Many different units have been used, for different materials and just for the products of different regions. Examples, showing the measurement base for each and the relationship to t as the equivalent number of tex, include those shown in Table 59.
Table 59(a)| Direct approach, measures of thickness: | index = units of mass per set length |
|---|
| Symbol | Unit of mass | Set length |
|---|
| Tt | tex | 1 g | 1 000 m | = 1 t |
| Td | denier | 1 g | 9 000 m | = 9 t |
| drex | 1 g | 10 000 m | = 10 t |
| poumar | 1 lb | 1 000 000 yd | = 2.015~ t |
| Tj | jute (also hemp, dry spun linen) | 1 lb | spindle of 14 400 yd | = 0.029 03~ t |
| Ta | Aberdeen | 1 lb | spindle of 14 400 yd | = 0.029 03~ t |
Table 59(b)| Indirect approach, measures of thinness: | index equals; units of length per set mass |
| Symbol | | Unit of length | Set mass | |
|---|
| American cut | cuts of 300 yd | lb | = 1654~/t |
| American run | lengths of 100 yd | oz | = 310.0~/t |
| NeC | Cotton | hanks of 840 yd | lb | = 590.5~/t |
| NeL | Linen | leas of 300 yd | lb | = 1654.~/t |
| Nm | Metric | lengths of 1000 m | kg | = 1000/t |
| Nt | Typp | lengths of 1000 yd | lb | = 496.1~/t |
| New | Worsted | lengths of 560 yd | lb | = 885.8~/t |
