Teasling. The operation of raising a nap on the surface of woven cloth; also called napping and gigging. Teasling is an operation applied with but few exceptions to woolen cloths, and usually is preceded by that step in the process of finishing called fulling or milling. The objects sought in the raising of naps are various. It may be for the procurement of warmth, as in the case of blankets and those varieties of flannels intended for garments to be worn next the body; or for the sake of appearance, as in chinchilla overcoating, and cotton drapery; or for the purpose of increasing the wearing qualities of a fabric, as in the case of cheviot and broad cloth. Woolen cloth intended to be teasled is first taken from the fulling-machine and stretched uniformly in all directions by hook on a frame, so that it may dry evenly without wrinkle or curl. When the cloth is nearly dry it is in proper condition to be teasled. The raising of the nap is effected by the agency of a thistle-like plant called the teasle. These oval teasle-heads are about 3 inches long by 2 inches in diameter, clothed with strong, sharp recurved hooks. They are an important article of commerce, being grown principally in Holland, France and Virginia. The scales or hooks which cover the teasle closely are possessed of high elasticity, combined with just sufficient stiffness for the work they have to do. The use of these is to scratch the surface of the cloth, and getting entangled with the minute surface fibers break these or pull out their ends, and so raise up over the whole surface a fine but unequal nap. Formerly the teasles were set together in a flat frame, like a large sized curry-comb, and by hand the workman brushed it over the whole surface of the tightly stretched cloth. But this laborious process has long been superseded by the use of the gig-mill or teasling-machine. This machine consists of a cylinder made to rotate at a high rate of speed. The teasle heads are fixed between slats over the whole surface of the cylinder, which is made to revolve against the surface of the cloth, just close enough so that the sharp hooks may scratch the surface and become slightly entangled with the minute surface-fibers of the cloth, and so break or pull out their ends. A self-acting arrangement regulates the lightness and closeness of contact of cloth and teasles. As already observed, there are many varieties of naps raised on the surfaces of woolen goods, and a nap may be raised in a certain class of fabrics for a purpose quite the opposite of that for which other naps are formed. Thus for instance, for one sort of fabric the object may be to get a nap which quite covers and conceals the underlying structure, while tweeds, cassimeres, and similar goods are teasled with the view of later on removing the nap from the surface and leaving the pattern of the cloth well defined and free from all hairiness. Fabrics upon which the nap is intended to lie smooth, flat, and level in one direction, as broadcloth or kersey, are dressed by the wet method, that is, the cloth is kept very damp during the entire process. Cloth raised dry, on the other hand, throws its fiber ends straight out and up from the warp and weft. In either case the cloth is next submitted to the operation of cropping or shearing, in order to leave the nap of a perfectly uniform length. The direction in which the nap lies, always indicates the warp of the fabric. Cropping was also formerly a handicraft, the worker using a huge pair of shears, and the employment demanded much dexterity and skill to a produce a smooth level nap. It is now done with equal rapidity and certainty by a machine which in principle is the same as the lawn-mower, used for cutting grass. It consists of a cylinder armed with a set of curved knives or cutters, revolving with great velocity against the stretched surface of the cloth, cutting away and breaking off the projecting fibers which come within range of its blades. Cloths upon which a nap of sufficient thickness has been raised may be finished with any fancy ridged, tufted, or waved-line surface desired, by simply having the blades of the shearing machine so notched as to cut away the undesired portions; or the nap may be pressed into various patterns by "stamping" between heavy iron rollers.

Much inventive talent has been expended in endeavors to provide some sort of metal or wire "teeth" to supersede the teasle for the purpose of napping goods, but a variety of experiments, extending over many years, and ending in dissapointment, have led to the conviction that no artificial substitute for the teasle can ever be found. This conviction has become so ingrained into the natures of nappers of woolen cloths that of late years they are extremely wary of new inventions. It is quite in the line of possibilities, however, that American inventive genius may eventually furnish an acceptable metal substitute, although up to the present time their productions have resulted in successive signal failures. Some classes of cotton goods, however, are now napped with wire, a description of which operation may be found under Outing Cloth. The value of the natural teasle for napping woolen goods lies in the fact that, unlike any metal "teeth," while sufficiently strong to scratch up the entire surface of the cloth, disengaging and opening the short fibers, and thus covering the whole with a nap, will at the same time break in contact with a knot or other obstacle, without injuring the cloth, while the metal teeth from the nature of their construction are too liable to break and tear the threads.