The physical state of epoxy resins can range from a low viscosity liquid to a high melting point solid. They can be 'cross-linked' using a variety of curing agents or hardeners to form a range of materials with a unique combination of properties, which bring advantages to key industry sectors. Epoxies are known for their excellent adhesion, chemical and heat resistance, outstanding mechanical properties and very good electrical insulating properties. Many of their properties can be modified, for example silver-filled epoxies with good electrical conductivity are available, whereas epoxies are typically electrically insulating. Variations offering high thermal insulation, or thermal conductivity combined with high electrical resistance for electronics applications, are available.