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 Narva Oil Plant Narva Oil Plant (), a subsidiary of Eesti Energia, is a producer of shale oil from oil shale. It operates a commercial scale shale oil retorting plant, located in Auvere near Narva, Estonia. The oil shale retorting plant (the UTT-3000 refinery) was built in the late 1970s next to the Eesti Power Plant to provide shale oil as a start-up fuel for the power plants. The plant was commissioned in 1980. Since the beginning of the 1990s, the oil plant operated as a part of the Narva Power Plants. In September 2007, the oil plant was separated