Oil paint considered drying, those with an iodine number of 115-130 are semi-drying, and those with an iodine number of less than 115 are non-drying. Linseed oil, the most prevalent vehicle for artists' oil paints, is a drying oil. When exposed to air, oils do not undergo the same evaporative process that water does. Instead, they polymerize into a dry semisolid. This rate of process can be very slow, depending on the oil. The advantage of the slow-drying quality of oil paint is that an artist can develop a painting gradually. Earlier media such as egg tempera dried quickly, which prevented the
Oil production plant Sometimes the produced oil may be "stabilised" (a form of partial distillation) which reduces vapour pressure and sweetens "sour" crude oil by removal of hydrogen sulphide, thereby making the crude oil safer for storage and transport. The production plant is said to begin after the production wing valve on the oil well. The product from each well is piped through the choke valve, which regulates the rate of flow. The flowlines are gathered at the inlet manifold and routed into a separator, which will separate the three components. Once the oil has been separated from the gas and produced water,