In shoe materials there is at present an astonishing diversity and variety. Every known leather is used from kid to cowhide, and textile fabrics have developed rapidly, especially in the making of women’s and children’s shoes. The satins, velvets, serges, and other fabrics that are used in the manufacture of shoes must be firm and well woven, and are usually supplied with a backing of firm, canvas-like fabric, to give strength.
As to wearing quality the old saying, “There is nothing like leather,” still holds good; but people do not buy shoes for their wearing qualities alone in these days. Style and intrinsic beauty are considered, and have a cash value just as in any other article of apparel.
Each fabric is made of two sets of threadlike yarn woven at right angles to each other. They are called the warp and filling (weft). The warp is composed of yarn running the longest way of the fabric, and filling runs the short way of the fabric. Since the warp is the body of the cloth, it is its strongest part and all fabric in shoes should be placed warpwise across the foot of the wearer, so as to be able to resist the great strain.
Various attempts have been made for legislation to prohibit the treating of leather by chemicals or the use of substances to increase its weight. Complaints have been made by a number of shoe manufacturers that the excessive use of glucose (a form of sugar) in sole leather has resulted in injuring the leather and fabrics composing the uppers of shoes.
Representatives of large leather firms claim that the methods of tanning sole leather have radically changed during the last few years, and that the small quantity of glucose and epsom salts that is used to-day in finishing sole leather is absolutely necessary to its value, and is in no sense an adulterant or weighting material. Shoe manufacturers, on the other hand, claim that in some cases larger amounts of glucose, salt, etc., have been added to the soft leather from the belly of the animal, in order to give it the desired stiffness. On account of the high price of leather, various attempts have been made to find a substitute for it. Most of these substitutes consist of strong cloth treated with some drying oil like linseed, the oil having previously been mixed with other solid substances.
A prize of five thousand francs has been awarded to a Belgian inventor, Louis Gevaert, for his unusually superior artificial leather. The process consists in the more or less intimate impregnation of stout cloth with tannic albuminoid substances. Shoes made of this are said to possess not only the resistance and elasticity of natural leather, but its durability of wear. Moreover, they are much cheaper, costing, including manufacture, only four francs (about eighty cents) and being sold at about six francs per pair.