Abstract: Vegetable oils or vegetable oil alkyds are emulsified in aqueous medium by means of a suitable emulsifying agent providing particles of oil or alkyd encapsulated in an oxygen permeable layer of emulsifying agent. The emulsified oil or alkyd particles are reduced to a predetermined size, and the emulsion is subjected to an oxygen-containing gas, preferably at elevated pressures, to effect autoxidation by cross-linking between olefin groups of unsaturated fatty acid moieties of the vegetable oils. Autoxidation is continued until the emulsified particles gel or nearly gel. When applied to a surface and exposed to air, the particles coalesce into a continuous film, and further oxidation and drying of the emulsion occurs.