Since 1967, an internationally used system of measurement for the fineness of fibres, yarns, spun yarns and slivers, irrespective of the type of fabric, which is also intended to replace the metric number, the English cotton number and the denier titre. It denotes the weight in g of 1000 m of fibre or yarn and can be converted to decimal, especially for spun yarns ktex = kilotex = gram weight of 1 m is used. The tex system simplifies the determination of twisting units because only the tex values of the yarns have to be added together to calculate the final twisting unit.
