Oil paint produce refined varieties of oil with fewer impurities, but many artists prefer cold-pressed oils. Other vegetable oils such as hemp, poppy seed, walnut, sunflower, safflower, and soybean oils may be used as alternatives to linseed oil for a variety of reasons. For example, safflower and poppy oils are paler than linseed oil and allow for more vibrant whites straight from the tube. Once the oil is extracted, additives are sometimes used to modify its chemical properties. In this way, the paint can be made to dry more quickly (if that is desired), or to have varying levels of gloss, like
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,