Oil painting the painting process is underway. An artist's palette, traditionally a thin wood board held in the hand, is used for holding and mixing paints of different colors. Pigments may be any number of natural or synthetic substances with color, such as sulphides for yellow or cobalt salts for blue. Traditional pigments were based on minerals or plants, but many have proven unstable over long periods of time; the appearance of many old paintings today is very different from the original. Modern pigments often use synthetic chemicals. The pigment is mixed with oil, usually linseed, but other oils may be used.
Narva Oil Plant from the power plants and the separate subsidiary of Eesti Energia was established. The retorting plant consists of two modified Galoter type solid heat carrier retorts (Enefit retort)—both processing 125 tonnes per hour of oil shale. Main products are fuel grade shale oil, raw material for bitumen and antiseptics. The designed annual capacity of the plant is 220,000 tons of shale oil and 60 million cubic meters of retort gas. In May 2009, Eesti Energia announced that it plans to build a new shale oil plant adjacent to the existing plant with processing capacity of 2.26 million tonnes of oil