General knowledge of oils applicable to painting

All vegetable oils are divided into:

• drying,
• semi-drying,
• non-drying.

We can divide the oils used in painting into two groups:
1. drying oils, oily, obtained from the seeds of various plants and belonging to the fats of plant origin, such as linseed oil, poppy seed oil, walnut oil.
2. volatile oils that do not belong to fats.

Drying oils

They have the ability to dry and harden in the air. This allows them to act as binders in painting.
Among the drying oils are linseed oil and hemp oil. They contain a lot of linolenic acid and oxidize in the air.

Semi-drying oils:

• cottonseed,
• corn,
• poppy seed,
• sunflower,
• soybean.

They contain a lot of linoleic acid.

Non-drying oils:

• almond,
• castor,
• coconut,
• palm,
• fistas,
• rapeseed,
• olive,
• sesame.

They contain a lot of oleic acid.
In painting, the most popular oils are:

• linseed,
• walnut,
• poppy seed.

They are non-volatile, colorless or colored thick liquids that do not combine with or dissolve in water. Lighter than water, they float to the top.
They dissolve with difficulty in spirit, while they dissolve easily in ether, hydrogen sulfide, chloroform and volatile oils.

Vegetable oils

They are composed, like vegetable fats, of charcoal, hydrogen and oxygen.
Chemically, they are very complex compounds, the more important component of which is the compound of fatty acids with glycerol, for which reason these oils are called glycerides.
Glycerides under certain conditions form soaps and release glycerin, which is why these oils are called "saponifiables."

Volatile oils

These are non-saponifiable oils. By their composition they belong mainly to hydrocarbons.
Some volatilize in the air without rest, others only partially. They also partially oxidize and form a solid.
Volatile oils that volatilize without remainder include products from kerosene and gas tar (benzene, toluol, xylene, tetralin, decalin).Most of them belong to substances with low chemical activity (mineral oils).
Volatile oils, which include turpentine (French), Capay balsam oil, copoly and amber oils, only partially volatilize, while partially oxidize and dry out. These are terpenes - chemically active bodies.
Volatile oils also include oils that are a mixture of hydrocarbons of the order of terpenes with some oxygen compounds:
rosemary oils,

• spicy,
• lavender,
• clove,
• elemi balm.