This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Yarn. Any textile fiber prepared by the process of spinning for being woven into cloth ; also, the term applied to woolen fiber prepared for hand knitting. All the yarns used for weaving purposes, whether made on "woolen," "worsted," or cotton systems, maybe divided into two great classes, namely: crossband and openband twists. The origin of this classification is derived from the twisting process. There are, as a simple experiment will show, two distinct methods of imparting twist to the attenuated sliver of the condenser. Suppose, for example, that a number of threads are about to be twisted together by hand ; in order to accomplish this, one end of the threads might be held in a fixed position between the forefinger and thumb of the left hand, while the right hand could be engaged in imparting twist to the fibers, causing them to twine around each other from left to right, and forming, by so doing, what would be an openband thread. To produce the opposite kind of a twist, called crossband, it would only be necessary to reverse the motion of the right hand, and thus cause the fibers. during the imparting of the twist to the sliver, to revolve from right to left. In making this or a similar experiment, the left hand corresponds to the wooden frame, which was in Hargraves' machine, substituted for the hands of the spinner, or to giving-off rollers of the spinning frame in present use; for these grip the thick thread, while the spindles give the necessary twist in the direction they revolve, like the motions of the right hand. Yarn always loses a portion of its length in twisting, the loss being proportionate to the thickness of the yarn, and the hardness of the twist. If two bobbins containing the same counts are twisted together, the count will become half of what it was before [See Thread], just as the weight will be double. In bleaching, cotton yarns also lose a part of their weight, amounting to about 12 per cent. By dyeing, on the contrary, they acquire additional weight, sometimes as much as 15 per cent. [See Hank, Factory]