Linseed oil for wood is available in two variants: boiled and raw linseed oil. Raw linseed oil is the pure version, which is pressed from flax seeds. It dries very slow. Boiled linseed oil is not obtained by simply boiling the oil, but is a mixture of linseed oil, standing oil (linseed oil heated without oxygen), and further processed by oxidation or adding metallic thinners(1).
Linseed oil can be applied as a transparent protective sealant for wood, in or outdoors. It is water resistant until a certain extend. It is also widely used as a painting medium in different (natural) paints, such as lime, clay and flour paint.