It is produced in a wide variety of types and styles, decorated by a wide range of techniques. It is more supple and pliable than vegetable-tanned leather and does not discolor or lose shape as drastically in water as vegetable-tanned. It vegetable tanning process pdf also known as wet-blue for its color derived from the chromium. More exotic colors are possible when using chrome tanning.
The chrome tanning method usually only takes a day to finish, and the ease and agility of this method make it a popular choice. However there are environmental concerns with this tanning method. It is supple and brown in color, with the exact shade depending on the mix of chemicals and the color of the skin. It is the only form of leather suitable for use in leather carving or stamping. This is a feature of oak bark tanned leather that is exploited in traditional shoemaking.
In hot water, it shrinks drastically and partly congeals—becoming rigid, and eventually brittle. This is the leather that most tanners refer to as wet-white leather due to its pale cream or white color. It is the main type of “chrome-free” leather, often seen in shoes for infants and automobiles. Brain-tanned leathers fall into this category, and are exceptionally water absorbent. They are known for their exceptional softness and washability. Rose-tanned leather tanned leaves a powerful rose fragrance even years from when it is manufactured. It has been called the most valuable leather on earth, but this is mostly due to the high cost of rose otto and its labor-intensive tanning process.
Alum-tanned leather is technically not tanned, as tannic acid is not used, and the resulting material reverts to rawhide if soaked in water long enough to remove the alum salts. Leather, usually vegetable-tanned, can be oiled to improve its water resistance. Leather with the hair still attached is called “hair-on”. The grain remains allowing the fiber strength and durability. The grain also has breathability, resulting in less moisture from prolonged contact. High quality leather furniture and footwear are often made from full-grain leather.
It has had the “split” layer separated away, making it thinner and more pliable than full-grain. Its surface has been sanded and a finish coat added, which produces a colder, plastic feel with less breathability, and it does not develop a natural patina. It is typically less expensive and has greater stain resistance than full-grain leather if the finish remains unbroken. The hides used to create corrected leather do not meet the standards for use in creating vegetable-tanned or aniline leather. The imperfections are corrected or sanded off, and an artificial grain embossed into the surface and dressed with stain or dyes.