1911 Encyclopædia Britannica/Twill

TWILL (connected with “ two ”), a woven cloth in which the passage of the weft is arranged, not in regular succession as in plain weaving, but over one thread and under two or more according to the kind of twill. This gives a succession of diagonal lines to the cloth, and though in the normal type of twill this diagonal traverses from selvage to selvage at an angle of 45°, considerable variations may be made. Twills may be stout and serviceable cloths, though, theoretically, it would seem that the strain of wear on the threads that compose the cloth is necessarily irregular. The twill or diagonal may run either from left to right or vice versa. Twills are made in most kinds of cloths—silk, woollen, cotton, &c.