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 shale per year. It would produce 290,000 tonnes of shale oil and 75 million cubic meters of oil shale gas per year. The cost of the new oil plant is approximately 3 billion Estonian kroons (€191.7 million, US$264.2 million). The construction was launched in the second half of 2009, and the new Enefit280 plant was commissioned in 2012. The first barrel of shale oil was produced in the new plant on 20 December 2012. 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