Genuine Leather (Corrected Leather)
Genuine leather can come from any layer of the hide, and undergoes treatment to the surface to provide a more uniform, “corrected”, appearance. It can be sanded or buffed to remove surface imperfections, then dyed (or spray painted) or stamped/embossed to give it a final surface appearance.
The process alters some of the preferred qualities of leather, so while not a top quality, it is often used for belts and similar goods.
Split Grain Leather
Split grain leather is a layered cut of leather from within the lower levels of the top grain area of the hide. It is usually a lower layer of the hide, above the flesh. Also, below the full grain and the best top grain cuts. Though, it still provides a useful leather material.
The natural surface of split grain leather is not as dense, tight, and useful as full grain and top grain. Thus, it is often used in finishes of leathers that are colored, embossed, and the surface altered in some significant way. This allows it to offer some of the helpful qualities of a leather material, while having a visually pleasing and often-functional surface beneficial for leather products.
Bonded Leather (Reconstituted Leather)
Bonded leather is like the scrapple or hot dogs of leather; it is made up of leather scraps that are finely shredded and bonded together using polyurethane or latex onto a fiber mesh or sheet. The amount of leather in the actual mix can vary greatly (from 10%-90%), and thus affect the functional and aesthetic properties of the finished product.
Bonded leather is often painted to give it color and could also be pressed/embossed to give it the appearance of a particular grain or leather style.