Bitumen (bituminous bodies)

Asphalt

It consists mainly of paraffinic hydrocarbons. In addition, it has sulfur and nitrogen compounds in its composition.
Asphalt in its natural state was mined from the shores of the Dead Sea. It was the so-called "Syrian asphalt" (the grade used in painting).
Asphalt in its raw state dissolves in oil and turpentine, so for painting purposes it must be properly prepared.
Usually Venetian turpentine, shellac, wax are added to it and everything is melted together.
Asphalt is characterized by its lasciviousness and pleasant tone, which is why many old masters, especially the Dutch, used it in their work.
They were able to prepare it well, as a result of which it did not do the kind of damage that paintings painted with asphalt did in the 19th century.
The characteristic feature of asphalt, and the most negative one, is that it has the ability to dissolve in oil and does not give a permanent painting layer. It forms a very wide and irregular grid of cracks. When laid in the lower layers it flows to the top affecting the upper layers. When exposed to light, it brightens slightly.
Wanting to use asphalt, it should be properly prepared and not mixed with other dyes and laid in one layer.
Nowadays, the so-called "Wibes brown" is produced, which is tonally close to asphalt and is absolutely durable. By chemical composition it belongs to mars. It is anhydrous iron oxide.

Egyptian mumia

A brown dye similar to asphalt, but not laser-like.
When exposed to light, like asphalt, it brightens, but is more durable than it.