Leather is made from the hides or skins of animals, birds, reptiles, and fish. Two main steps are involved in this process. First, the hides or skins are cured or dressed to prepare them for tanning. This curing process removes all the flesh, hair, and foreign matter. The hides are then tanned to produce durable, useful leather.
There are two general tanning methods — (1) bark or vegetable and (2) chrome tanning. In chrome tanning, salts of chromium are used to process the hides. Chrome-tanned leather cannot be tooled, but it can be dyed and embossed.
Vegetable tanning makes use of the tannic acid that is found in bark, leaves, and other vegetable products. Leather made by vegetable tanning is tool able and is, in general, the most suitable for leather craft.
Tanned leather, which is about the color of human skin, is smoother grained, but can be further finished by dyeing, glazing, buffing, graining, or embossing.
While the better leathers are usually left smooth, those having scratches, flaws, or other surface defects after tanning are generally embossed with a grain.
Leather can be purchased in many sizes and thicknesses. The thickness of leather is expressed either in ounces or fractions of an inch. When ounce is used it is really a measure of thickness, and not of weight. Leathers range from about 1 to 8 oz. The weight to use depends on the end-service requirements.
Types Cowhide
This is a strong, tough, durable leather available in a wide variety of grades, types, weights, finishes and colors. Heavy vegetable-tanned cowhide back leather, ranging from 6 to 8 oz, is widely used for tooling, carving, and stamping. Heavy cowhide sides, sometimes called strap leather, are also suitable for tooling deep designs. Shoulder pieces are widely used for belts. Thinner cowhide, both vegetable and chrome tanned, is used in leathercraft kits. Cowhide belly, lowest in cost and quality, can be used where appearance and durability are not important.
Calfskin
Calf has the finest grain of all tooling leathers and is therefore best for tooling. It ranges in weight from 1.5 to 3.5 oz; it is more expensive than cowhide. When moistened and tooled on the grain side, the designs will remain permanently. Calfskin is available in natural finish or in a variety of colors. Chrome-tanned grades are less expensive than the tooling grades and are excellent for lining. (Vegetable-tanned calfskin is known as saddle leather.)
Steerhide
Steerhide has a crinkly surface, ranges in weight from about 2.5 to 4.5 oz, tools easily, and is not readily marred. It is available in many colors and in three-toned combination finish.
Sheepskin
Sheepskin is available in both tooling and nontooling grades. The largest nontooling use is for linings. Several types are available: suede, the best of lining leathers; skivers, thin and lightweight; glazed, with a fine, smooth glossy finish and firm texture. All these are available in many different colors, and are generally inexpensive.
The tooling grade is economical and tools without difficulty. Relatively deep tooling is also possible, but the leather should be dampened only very lightly. Sheepskin is often embossed or dyed to resemble calfskin.
Goatskin or "Morocco"
Although goat is naturally a fine-grained, smooth leather, it is most commonly seen with the pebbly or crinkly "morocco" grain produced by boarding. It is stronger and more attractive than sheepskin of the same finish. In the heavier weights it is suitable for tooling line design and initials. Morocco leather is used extensively for book covers. Glazed goatskin has a high gloss, firm finish, and is excellent for lacing things.
Kidskin
Exceptionally thin, smooth, and strong, kidskin is characterized by tiny holes on the grain side. Excellent for lining, and available in various colors, it is used for lining, handbags, book covers, and wallets.
Pigskin
This leather has a fine grain and smooth surface with visible holes in groups of three. The finest grades are usually imported. Tooling of pigskin is very difficult and not recommended. It is an expensive leather and therefore its use is confined largely to small parts such as billfolds, card holders, and pocket secretaries.
Suede
Suede can be made from many kinds of leather, but most commonly from sheepskin. It has a soft velvet finish, is nontooling, and is suitable as a lining as well as for garments. Velvet Persian is a high-quality suede from skins of Persian sheep.
Alligator
Alligator is very expensive and is therefore restricted to small products. Besides genuine alligator, simulated alligator-grain leather is also available. It is usually made from calfskin or cowhide. It is attractive, strong, non-tooling, available in many colors, and relatively inexpensive.
Snake and Lizard
Reptile skins are specialty leathers noted for the beauty of their markings. The skins are durable as well as beautiful. Because they are quite expensive, they are used only for very small items.
