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
Jojoba oil and climate in which the plant is grown, as well as when it is harvested and how the oil is processed. In general it contains a high proportion of mono-unsaturated fatty acids, primarily 11-Eicosenoic acid (Gondoic acid). Being derived from a plant that is slow growing and difficult to cultivate, jojoba oil is mainly used for small-scale applications such as pharmaceutical and cosmetics. Overall, it is used as a replacement for whale oil and its derivatives, such as cetyl alcohol. The ban on importing whale oil to the U.S. in 1971 led to the discovery that jojoba oil is "in