(c) Oleo-resinous The vehicle incorporates natural or artificial resins into drying oils. Some of these resins may react with the oil to give a faster drying vehicle. Other resins do not react with the oil but heat is applied to dissolve the resin and cause the oil to body.
(d) Alkyd resin These vehicles provide a further improvement in the drying time and film forming properties of drying oils. The name alkyd arises from the ingredients, alcohols and acids. Alkyds need not be made from oil, as an oil-fatty acid or an oil-free acid may be used.