Linseed oil has been used for many years as a wood finish and preservative. The oil is obtained from dried flax seeds through a chemical process. Linseed oil is water resistant and when applied to wooden materials, fills the pores in the wood and provides a shiny coating.
Linseed oil used for wood preservation comes in three forms: pure, boiled and polymerized. Pure linseed oil is ideal for use on wooden products that may come in contact with food. Boiled linseed oil has drying agents that make the drying process quick. Polymerized linseed oils are said to be more durable than other types of linseed oils.