Mixtec writing has been preserved through various archaeological artifacts that have survived the passage of time and the destruction of the Spanish conquest. Among these objects are four pre-Hispanic codices written on tanned deer skin covered with stucco. These codices are read in boustrophedon, a zigzag style in which the reader follows red lines that indicate the way to read. Most of the current knowledge about the writing of the Mixtecans is due to the work of Alfonso Caso, who undertook the task of deciphering the code based on a set of pre-Columbian and colonial documents of the Mixtec culture.