Soybean oil is a vegetable oil extracted from the seeds of the soybean (Glycine max). It is one of the most widely consumed cooking oils and the second most consumed vegetable oil. As a drying oil, processed soybean oil is also used as a base for printing inks (soy ink) and oil paints.
Soybean oil is one of many drying oils, which means that it will slowly harden (due to free-radical based polymerization) upon exposure to air, forming a flexible, transparent, and waterproof solid. Because of this property, it is used in some printing ink and oil paint formulations. However, other oils (such as linseed oil) may be superior for some drying oil applications.