 Although numerous types of writing surfaces were used, such as stone, bone, metal, and ceramics, the most famous surviving artifacts are the codices.As in other regions, codices were made from long strips of material folded into an accordion shape; in this region, bark from the amate tree, agave fibers, and/or animal hides were used as paper, and the codices were protected by wooden covers.The Nahuatl codices (containing works from the Aztecs, Maya, and Mixtecs, among other tribes in the Nahua language family), are the most famous of these.