Fat over lean

[dead link‍][1] Oil paint dries at different rates due to the differing drying properties of the constituent pigment.

Conversely, the lower the oil content, the faster the paint dries, and the more brittle it will be.

that the 'fat-over-lean' principle can be circumvented by using synthetic, alkyd-based painting media such as Galkyd and Liquin.

These media do provide consistent drying times, increase the paint film flexibility, and promote adhesion between paint layers.

However, because classical painting media, turpentine, natural resins, and certain plant oils (linseed, walnut and poppy) have lasted for centuries when applied properly, some artists choose to avoid synthetic media since their long-term stability is unknown.