After the New Kingdom (1069 BCE–395 CE)
Throughout Egyptian history the tombs of the wealthy and royal were robbed for their immense riches. Coffins, mummies, and wrappings were torn apart to get to the gold and precious stones inside. During Dynasty 21, many of the royal mummies whose tombs had been robbed were reburied with all the proper ceremonies to ensure their continued existence in the afterlife.
During this process of reburial many noticed that though the New Kingdom method of drying the body preserved it, the appearance of the body was not very lifelike. Thus a new step was added to the mummification process. Before wrapping, packing materials, including linen, fat, mud, sand, and sawdust, were placed under the skin to fill out the body surfaces. Also, the viscera, instead of being put in canopic jars, were wrapped up with figures of the sons of Horus and re-packed inside the body. The outside surface of the mummy was then painted, giving it a doll-like appearance. Unfortunately, sometimes the packing materials changed over time and caused some of the bodies to swell.
After Dynasty 21, the art of the embalmer rapidly declined. By the time Egypt was conquered by Persia, Greece, and Rome, a wide range of people were being mummified. Embalmers could not afford to take the time they had taken before, and often bodies had already started to decay before the experts could get to them. X-rays of mummies from this time period show wrappings that cover incomplete bodies with missing parts replaced by bones, pottery, or palm fibers. Instead of using the traditional methods for embalming, the embalmers covered the bodies with a black resin like bitumen from which we get the term mummy, which is Arabic for "bitumenised thing."
The emphasis for these later mummies was not on the treatment of the body but on the external additions. Within the bandages were wrapped masks, breast plates, and foot coverings made of cartonnage. During the latest periods of ancient Egypt, portraits of the deceased were painted on thin wooden boards and wound into the bandages. The bandages themselves were wrapped in elaborate, diamond-shaped patterns. The centers of the patterns were often decorated with gilded (gold-covered) studs.
It is unfortunate that our earliest complete narrative of mummification comes to us from this Late Period of Egyptian history. A text from the ancient Greek historian Herodotus (c. 440 B.C.E.) is instructive for comparison with the conclusions of modern scientists studying the process, like A. Lucas
Once the mummification process was completed, the funeral ceremonies began.
"You are pure, your front is pure, your back parts are clean by means of natron, fresh water, and incense, and you are pure by means of milk of Apis, by beer of Tjenmyt, and by natron which dispels the evil on you." Spell 169 - The Book of the Dead