Man-made or synthetic resins include epoxy resin, used as a vehicle for paint because of its durability. Epoxy-based paints are sometimes used on goods such as refrigerators and cookers and to protect steel pipes and fittings from corrosion. Other examples of artificial resins include acrylic, used to make acrylic paints. Epoxy resin and some other synthetic resins are associated with negative effects such as occupational asthma or environmental damage.
Linseed oil is used to make varnishes and oil paints. Linseed is a siccative or drying oil: an oil which forms a tough, solid film when left exposed to the air for a sufficient time. Oil paints using linseed oil are common in fine art.
Mastic is a clear resin derived from the sap of a Mediterranean shrub. It can dissolve in turpentine and serve as a varnish or a vehicle for paint. The ancient Greeks probably used mastic to make the brightly-colored paints they used to decorate their statuary. Mastic is clear and almost colorless at first but quickly yellows with time.
Damar, also spelled dammar, is a natural resin. It is similar to mastic but is superior in quality. It is hard, durable and does not yellow. Damar comes from a species of tree native to South Asia. Damar is a renewable resource; it can be harvested without harming the trees that produce it. Like mastic, the ancient Greeks used damar in paints. It comes in solid chunks which can dissolve in gum turpentine (turpentine derived from plant sources) but not in mineral turpentine.
Copal is a hard resin derived from tree sap. The copal artists use was once amber: fossilized resin. Amber is now too expensive and hard to come by for most artists. Copal is not soluble at room temperature; it needs to be heated with a solvent before it can serve as a paint medium. Although it has many useful properties, copal resin darkens with age and tends to be brittle. Most commerically available copal media today do not contain any real copal resin, but have synthetic substitutes.