Book excerpt: Composites are the fastest growing class of structural material. Consequently, electronic properties are often difficult to find. The report was prepared in order to present a compilation of reliable data on the electronic and electrical properties of composites. The report provides a compilation of the most commonly required electronic properties data of structural composites. Thermal properties often influence electrical design; consequently several of these properties are included. The specific properties tabulated are: Arc resistance; Arc tracking resistance; Dielectric constant; Dissipation factor; Electrical (volume) resistivity; Electrical (volume) conductivity; Thermal conductivity; Linear thermal expansion coefficient.