Linseed oil is derived from the seeds of the Flax plant. Linseed oil is yellow in colour. Linseed oil has resolvent properties, thereby making it highly useful for industrial applications. It is a slow-drying liquid with good preservative properties and water resistance. It is generally used outdoors, and can take up to three weeks to dry. It prevents corrosion and dry rot. It has long been used as a drying oil, a vegetable oil which undergoes oxidation and forms a natural, plastic-like film. The reactivity of Linseed oil can be improved by the addition of metal catalysts, called driers, which promote oxidation, and by partially pre-oxidizing the Linseed oil through exposure to the air. It was found that the addition of solvents such as Mineral Spirits, Japan drier, and Turpentine would speed Linseed oil's drying time, making it a more useful product. It is a versatile substance, depending upon how it is processed. It is used in various industries.