Oil obtained from the seeds of a plant belonging to the Linaceae family (Linum usitatissimum). It is certainly the most widely used binder in the history of oil paint. Due to its high content of unsaturated fatty acids, it has excellent drying properties, which are particularly effective in boiled linseed oil. To limit the yellowing that occurs over time, it can be used in emulsion with walnut oil or poppy seed oil. Even without these precautions, it has the ability to transform during drying into films with excellent mechanical and optical properties, particularly suitable for the formation of image layers. The drying process includes a first phase of self-oxidation, which lasts about forty-eight hours, and a second phase in which oxidation and polymerization phenomena take place, lasting several - 10 years. The complete drying of linseed oil leads to its transformation into linoxin: this process gives special stability and strength to the pigment-binder structure.
