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.
Fulling. The process of condensing a previously formed fabric, causing it to assume a stronger and firmer body; especially applied to woolen goods. The first operation which a cloth that is to be fulled undergoes, after it is woven, is braying, the object of which is to get rid of the oil used preparatory to spinning, and also to get rid of the size used in dressing the warp. The cloth as it leaves the loom is greasy and rough, and is subjected to a number of processes which make it compact in texture and smooth and level in surface. In this operation the scouring stocks are used, which, under the more modern name of fulling mill, are supposed to stand, in point of antiquity, next to the corn or flour mill. Everyone is familiar with the fact that blankets and flannels tend to contract with frequent washings, gaining in thickness and solidity what they lose in strength and elasticity; such shrinkage is greatly hastened when woolen fabrics are rubbed in very hot water. This shrinkage is the result of the curly, scaly structure of wool fibers. The operation of fulling is now performed by a steam fulling mill. The old method of fulling by the stocks is wasteful of power, and the blows the stocks give with the heavy wooden mallets tend to sometimes tear and bruise the cloth, drawbacks from which the fulling mill is free. The cloth to be fulled is, after braying, first well saturated with hot water and soap, and pressed and rolled, and scoured and rubbed between the slow-revolving rollers of the fulling-machine while so heated and soaped. The more prolonged the operation the more does the woolen material shrink up and thicken. Twelve hours in the mill will reduce a piece of cloth two-fifths of its breadth, and one-third of its length, though it is possible to carry the operation to the extent of reducing cloth to one-half of its original length and breadth. The amount of fulling they receive is the distinguishing feature of many varieties of cloth. In the treatment of broadcloth, doeskin, melton, and all nap-finished woolens, the fulling is carried so far that the fibers become densely matted, obliterating all the appearance of the weave, and giving the piece more the aspect of felt. Fabrics to which no nap-finish is given are fulled only to the extent of solidifying the substance and strength of the texture. Tweeds are very slightly fulled in order to give them a "dressed" surface. The traveling motion of wool under the combined action of heat and moisture, resulting in the entanglement of the fibers and consequent fulling and shrinking of the cloth, is further exemplified in the case of Scotch caps and the hose shipped to the inhabitants of northern latitudes. The latter are first knit of a size sufficiently large to enclose the body of a man, and afterward fulled down to fit the foot. During the fulling of any and all kinds of goods, they must be frequently taken out and stretched, turned, the folds straightened and generally inspected. On conclusion of the opeiation the goods are scoured to free them from the soap, which is very simply done with pure water, tepid at first, but gradually cooled by additions till in the end the cloth is worked in pure cold water. [See Felting, Broadcloth, Teasling, Singeing.}