What were mummy's portrait masks made of?
the Encyclopedia Britanica-1991, Mask,... funerary masks and death masks were used in aincient Egypt and were associated with the return of the spirit to the body. Such masks were generalized portrates and, in the case of nobility, were made of precious metals. Gold death masks also appear in Aisa and the Incan civilization....
Most mummies' masks were made of cartonnage -- a paper product.
http://www.virtual-egyptian-museum.org/Collection/Material/Collection.Material-FR.html
The mummy's portrait masks were made of various materials, depending on the time and location. According to the Encyclopedia Britannica from 1991, in ancient Egypt, funerary and death masks were associated with the return of the spirit to the body. While generalized portraits of mummies were made, masks belonging to nobility were often made of precious metals such as gold.
However, for most mummies, their masks were made of a material called cartonnage, which is a type of paper product. Cartonnage was primarily made by layering linen or papyrus soaked in a plaster-like substance. The resulting material was then molded into a mask shape and decorated with paint, gilding, and other embellishments.
If you want to learn more about this topic, you can refer to the Virtual Egyptian Museum's collection of materials, where you can find information about the materials used for mummy masks and other artifacts from ancient Egypt.