A good quality hide is chosen, and given a long and mellow liming of about 15-16 days. The one-pit system may be used, and the hides are put into an old lime for about five days with frequent handling and then placed in a new lime which is made up in a pit containing about a foot depth of the old liquor. After about twelve days another ⅓ cwt. of lime may be added.
After unhairing and fleshing the goods are bated in pigeon dung for four days at a temperature of about 78° F., handling twice on the first and last days. The bating is stopped and the deliming completed by paddling with boric acid (15 lbs. per 100 butts).
The tannage is commenced by paddling in a spent handler liquor (4°) to which a little gambier has been added. The butts then go through the first handlers (5°-15°), which are rounds of ten pits in which the goods are handled every day in the first week, and alternate days in the second week, and are shifted forward twice a week in the next pit. The goods are therefore in this set for five weeks. Gambier is added to these liquors as needed. The butts next pass to duster rounds of four pits, in which they are dusted down in a liquor of 20° for four weeks with 1-2 cwt. of oak bark. The liquor is obtained from the leaches, and afterwards run alternately to the leaches and to the first handlers. As many as six layers are now given of 20°-25° strength, in which the butts are dusted down with 2-3 cwt. oak bark for three weeks. The layer liquors are received from and returned to the leaches, which are made from the "fishings" from the layers. The tannage lasts, therefore, 27 weeks, of which 18 weeks (two-thirds) are in layers.
Shorter tannages are now often given, using stronger liquors, much as in ordinary dressing leather.
The tanned butts are rough dried, and then wet in for shaving. They are thoroughly scoured, flesh and grain. They are next drummed for three-quarters of an hour in sumach, struck out and hung up to samm. Hand stuffing is best, to avoid any tendering owing to high temperature, but drum stuffing is also used. After setting out and stoning on the grain they are stuffed with warm cod oil and laid away in grease for several weeks, re-oiling occasionally. They may be stained before stuffing.
REFERENCE.
Bennett, "Manufacture of Leather," pp. 203, 310.
PART II.—SKINS FOR LIGHT LEATHERS
SECTION I.—PRINCIPLES AND GENERAL METHODS OF LIGHT LEATHER MANUFACTURE
The term "skin," like the term "hide," in its widest sense applies to the natural covering for the body of any animal, but is generally used with a narrower meaning in which it applies only to the covering of the smaller animals. Thus we speak of sheep skins, goat skins, seal skins, pig skins, deer skins, and porpoise skins. It is in this sense that it will be used in this volume. The treatment of such skins to fit them for useful purposes comprises the light leather trade. Whilst this branch of the leather industry is certainly utilitarian, the artistic element is a great deal more prominent in it than in the heavy leather branch. Thus the light leathers are often dyed and artistically finished, and their final purposes (such as fancy goods, upholstery, bookbinding, slippers, etc.) have rather more of the element of luxury than of essential utility. The total weight and value of the skins prepared, and of the materials used in their preparation, are naturally considerably smaller than those of the heavy leather trade. In the latter, moreover, one has to consider the purpose in view from the very commencement of manufacture and vary the process accordingly, but in light leather manufacture one aims rather, in the factory, at a type of leather such as morocco leather, and only after manufacture is it fitted to such purposes as may be particularly suited to the actual result. These results depend very largely upon the "grain pattern" which is natural to the skin of any one species of animals. Hence in Part II. of this volume it has been found most convenient to deal with the different classes of skins in different sections. Just as the hides of ox and heifer were much the most numerous and important of hides, so also naturally are sheepskins the most prominent section of the raw material of the light leather trade. This is the more true because the skin is valued for its wool as well as for its pelt; indeed, the wool is often considered of primary importance, and receives first consideration in fellmongering. Unfortunately for the light leather trade, sheepskins, though most numerous, do not give the best class of light leather, the quality being easily surpassed in strength, beauty and durability by the leather from goat or seal skins.