Alkyd resins may be hard, rigid, soft, balsam‐like, flexible and rubbery. Such alkyd resins as are typical of the more common states were prepared and investigated. During the formation of unmodified alkyd resins, there occurs a progressive increase in electrical resistance with time, temperature of preparation being constant. No abrupt change in resistance was obtained with the heat convertible resins as they gelled. Mobility is shown to be an important factor in influencing the resistance of a resin during formation since the heat convertible resin shows a much higher resistance for a given per cent esterification than does the heat non‐convertible resin. It is suggested that electrical resistance may be conveniently used to study and follow resin formation. High dielectric losses and, to some extent, high effective dielectric constant of synthetic resins result from some form of conduction in the resin. Curing the resins improves the electrical properties by allowing the chemical reactions to continue, or by driving off volatile products, or by reducing the proportion of conducting to nonconducting components. At high temperatures the thermoplastic resins, because of their tendency to liquefy, are poorer electrically than heat convertible resins. In general, dielectric losses are greater at high temperatures than at low temperatures because of the increased conductivity of the conducting components remaining in the resins. Differences in electrical properties of heat convertible and heat non‐convertible resins are in agreement with differences in their physical structure. Of the three mechanisms postulated as being possible explanations of observed electrical characteristics having a critical frequency (fm) (Fig. 7), polar orientation in a viscous medium seems least probable, while conduction in the solvating component of a gel structure seems most probable.