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. Oils have been used as a painting medium for centuries and mixing techniques and pigment types remain the same. The quality of the paint is determined by the raw pigment content. Cheaper oil paints use synthetic pigments and will not have the same vibrancy and colour density of traditional oil paints made from natural pigments.
Oils paints may take several weeks to dry completely, this allows the artist time to blend, mix and vary the composition of the painting.