An Alkyd Resins is a polyester modified by the addition of fatty acids and other components. They are derived from polyols and a dicarboxylic acid or carboxylic acid anhydride. Alkyd coatings have typically three classes based on the oil length in the resin: long, medium and short. Alkyd Resins are used in paints and varnishes. They are the dominant resin or “binder” in most commercial “oil-based” coatings.

Medium oil alkyds dry faster than long oil alkyds. The solvents are typically aliphatic or oxygenated. Characteristics of Medium oil alkyid have good durability and gloss retention. They are excellent for high gloss coatings and wood finishes.