Why is linseed oil used in traditional oil painting?

Linseed oil is used in traditional oil painting primarily because it is classified as a drying oil. When spread into a thin film, it reacts with exposure to air to thicken and harden into a tough, elastic surface.12

In the context of oil painting, linseed oil serves as the essential vehicle for the medium. Artists mix dry powder pigments with refined linseed oil to create a smooth, buttery paste that allows for unique textural variations, the fusion of tones, and the ability to apply paint in both opaque and transparent layers.32

Beyond its role as a binder, linseed oil is valued for its historical reliability and its ability to be refined to meet the specific technical requirements of the artist. While raw linseed oil dries slowly, other grades—such as boiled or blown oil—can be used to accelerate the drying process or create harder films. Because of these chemical properties, it has remained a foundational material for artists since the 15th century.132