Type of leather

What is the difference between top grain and full grain leather?
Full grain leather is the best leather which can be 3 to 5mm thick. It comes from the top layer of the hide. The surface of full grain leather burnishes and beautifies with use. As a matter of course, natural full grain has scars and dermatoglyph, therefore there is only about 70 to 80% can be used. Some full grain leather receives spray paint as make-up, to look smoother and shinier, but it may end up looking like cheap leather. Top grain leather is the second highest grade because it is split from the top layer of blemished hide then sanded and refinished. With a layer of plastic imitation leather, this part can be free of scars and scrapes. It’s price is much cheaper than full grain leather. Full grain leather with good quality is rare, that’s why its value is so high. Alto insists to use high quality full grain leather for the products, each item has its unique natural marks. We wish to share the beauty and value of fine leather with you.
Top Grain Leather
The distinction between the categories of a Top Grain leather and Full Grain leather are important. Top Grain leather refers to the process of sanding away the natural grain from the top surface of the leather. Imitation grain gets stamped into the leather to give a more uniform look, but no genuine grain remains. The word "top" often confuses seekers of the finest leather because it infers that it is "the tops" in quality.
Full Grain Leather
The real "tops" in quality is Full Grain leather. The best upholstery Full Grain leathers should display the natural markings and grain characteristics from the animal of which it was taken. Full Grain leathers generally come from a better quality hide or skin and no sanding processes are applied to its surface. Full Grain leathers offer a natural look and feel and are treated by transparent aniline dyes.

Corrected Leather grains
Corrected Leather grains fall into the Top Grain Leather category. These leathers go through considerable processing of sanding, buffing, stamping and then dyeing. The purpose of this processing is to create a uniform look that removes insect bites, barbed-wire scratches and other environmental markings that might appear on the hide. Corrected Leather grains fall into the next 18% of leathers.
Split Leather 
Split leather is leather created from the fibrous part of the hide left once the top-grain of the rawhide has been separated from the hide.
During the splitting operation, the top-grain and drop split are separated. The drop split can be further split (thickness allowing) into a middle split and a flesh split. In very thick hides, the middle split can be separated into multiple layers until the thickness prevents further splitting. Split leather then has an artificial layer applied to the surface of the split and is embossed with a leather grain (bycast leather). Splits are also used to create suede. The strongest suedes are usually made from grain splits (that have the grain completely removed) or from the flesh split that has been shaved to the correct thickness. Suede is "fuzzy" on both sides. Manufacturers use a variety of techniques to make suede from full-grain. A reversed suede is a grained leather that has been designed into the leather article with the grain facing away from the visible surface. It is not considered a true suede.