Nowadays, functional properties such as water repellency, breathability and fabric hand etc, required for textile products are important for physical comfort. In order to realize those properties, not only various types of functional finish but also complex weaving designs come to be important.

Moreover, there is great demand for improvement in the aesthetic appearance of functional finished fabrics.

Those requirements for the aesthetic appearance of functional finished fabrics also include visible functional properties after laundering in practical use of textile goods.

The value of merchandise comes to depend upon both functional properties and the aesthetic appearance of textile goods.

This important factor of aesthetic appearance is very much influenced by the weft distortion problem.