Full-grain, top-grain, genuine, and bonded leather explained side by side. Full-grain is the top layer of the hide, untouched, and the only grade that develops a real patina and lasts decades. Top-grain is sanded and coated, genuine is a legal label for low-grade splits, and bonded is leather scrap glued together. Here is what actually separates them, in a quick comparison table plus the reasoning behind each grade.