Explanation
Animal and vegetable fats and oils that can form a solid film in a relatively short time after being coated as a film and exposed to the air are called drying oil, while those that cannot form a solid film are called non drying oil; Although it can form a solid film, it takes a long time and has poor film strength, which is called semi dry oil.
Classification
Organic polymer materials -> Adhesives and coatings -> Coatings