The strongest and most durable part of the hide of an animal is just below the hair. The grain pattern in this part of the hide is very tight, and the leather made from here is called "full-grain" leather. Full-grain leather is the strongest and most durable leather. Additionally, since the grain is so tight, it resists moisture very well. Over time, full-grain leather will look nicer and nicer and develop a patina from being handled.
The next best—and second strongest—leather is called "top-grain" leather. Top grain leather is similar to full-grain leather, except that the top couple millimeters have been sanded and buffed to take away imperfections. With the top layer removed, the leather will have a more uniform finish, but it won't be as durable—and it will break down much faster. This is more of a "cookie cutter" leather that most leather wallets and handbags are made of, which lends to their generic appearance. Top-grain leather can be good leather, but its strength and durability is not even close to the strength of full-grain leather.
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