Tempera technique in ancient Egyptian murals.

The colours of the murals remain on the walls of tombs and temples in ancient Egypt, they retain their splendour and splendour, and their colours have not changed despite the passage of thousands of years, which made them astonishment to all who watched them!

Here is a simplified attempt to shed light on the use of colours in ancient Egypt and the technique of their use.

** First, we must know that there are two basic methods for using natural oxide colours in colouring on the walls of Egyptian tombs and temples,

The first is a style called water tempera.
The artist was preparing the photographic floor to receive the colour matter properly after grinding and smoothing it to penetrate the stone mass through the pores.
In this case, the artist sprayed the stone with a little water before he signed the drawing on the limestone to control the colour without causing any distortion or smearing of the colours.
And the artist used water as a medium carrying colours, as in this case, the stone absorbs water and is loaded with a large amount of oxide dissolved in the water to settle in the pores of the stone, and the rest of it forms a colour layer on the surface of the stone.
Then comes the isolation phase.

The second type is egg white tempera.
The artist used to dissolve the oxide in the egg white as a colour-carrying medium and then use it directly on the stone’s surface, as is the case in the Beni Hassan cemeteries in Minya Governorate.
This is what we will show later.
This is unlike other bearing floors such as plaster or wood, and the method differed according to the floor or artist,

* How to reach the raw materials of different colours.

Through observation and experience, the ancient Egyptian knew the properties of minerals and stones from the surrounding environment. It worked as much as possible to adapt and benefit from them to serve the purpose he wanted.
Among the most common colours in temples and tombs paintings are dark brown, yellow, green, blue and black, and to obtain these colours, he resorted to the environment.

Here are some of the minerals from which he obtained these colours.

Reddish-brown colour, which is the skin colour from ferric oxide (Fe2O3) (Hematite).

Black hair colour from ferrous oxide feo2

– The green colour of hydrated copper carbonate (Cu2CO3 (OH .)

Blue from basic copper sulfate or blue vitriol

– Yellow colour of iron(III) hydroxide (Fe(oH .)
The white colour of calcium carbonate (limestone) caco3

Tempera.
How was the ancient Egyptian able to install these colours and maintain their stability?
It was necessary to use these oxides to be dissolved in a liquid to spread them on the walls. Therefore, he dissolved them in water, where they remain suspended in the water, and when colouring, the stone absorbs the water and keeps the colour layer suspended on the stone’s surface. Then he uses the white leek. (Egg white) as a varnish material whose mission is to isolate the oxide from atmospheric influences so that the colour does not change due to the interaction of the oxides with atmospheric air.
Oh.
It dissolves the colour in the egg white directly and uses it as an oxide carrier medium, and uses it in colouring.
And the egg white remains as a medium and an insulating substance for the colour.
Why egg whites?
Egg white is a transparent substance that does not affect the colour and does not interact with it, and when it hardens, it becomes part of the stone and is difficult to fall off on its own.

The difference between the method of tempera with water and egg white tempera.
In water tempera, the colour can be removed easily if the artist made a mistake during the work; here, it is easy.
Correct the error
In the case of egg white tempera, it is difficult to fix any errors due to the speed of drying the colour and reaching a high degree of hardness.

And this method is generally used to colour the surfaces in an opaque way to cover the surface bearing the colours because the oxides used are basically opaque.
This method is still used now, and it is called the gouache colours, which come in their commercial form ready to work, including opaque and transparent to suit different projects.