<P> Oil paint is a type of slow - drying paint that consists of particles of pigment suspended in a drying oil, commonly linseed oil . The viscosity of the paint may be modified by the addition of a solvent such as turpentine or white spirit, and varnish may be added to increase the glossiness of the dried oil paint film . Oil paints have been used in Europe since the 12th century for simple decoration, but were not widely adopted as an artistic medium until the early 15th century . Common modern applications of oil paint are in finishing and protection of wood in buildings and exposed metal structures such as ships and bridges . Its hard - wearing properties and luminous colors make it desirable for both interior and exterior use on wood and metal . Due to its slow - drying properties, it has recently been used in paint - on - glass animation . Thickness of coat has considerable bearing on time required for drying: thin coats of oil paint dry relatively quickly . </P> <P> The technical history of the introduction and development of oil paint, and the date of introduction of various additives (driers, thinners) is still--despite intense research since the mid 19th century--not well understood . The literature abounds with incorrect theories and information: in general, anything published before 1952 is suspect . Until 1991 nothing was known about the organic aspect of cave paintings from the Paleolithic era . Many assumptions were made about the chemistry of the binders . </P>

The most common medium for oil paint is