Uhle categorized the types of mummification he saw into three categories: simple treatment, complex treatment, and mud-coated mummies. He believed that these occurred chronologically, the mummification process becoming more complex as time went on. Since then, archaeologists have expanded upon this explanation and have (for the most part) agreed upon the following types of mummification: natural, black, red, mud-coated and bandage mummies. Mummification can also be described as "externally prepared" mummies, "internally prepared" mummies (Egyptian Pharos), and "reconstructed" mummies (the Chinchorro), according to Andean Archaeologists. Further, it turns out that the types of mummification used overlap with each other, and mummies of different types have been found all in the same tomb. The two most common techniques used in Chinchorro mummification were the Black mummies and the Red mummies.