The dielectric constant tends to be high in insulating materials, such as ceramics and plastics. Insulators are materials that have very low electrical conductivity, which means they do not allow the flow of electric current easily. This characteristic makes them good dielectric materials with high dielectric constants. Insulators have a large number of bound electrons, and when an electric field is applied, these electrons get polarized, resulting in the accumulation of electric charge within the material. The ability of insulators to store a significant amount of electric charge leads to high dielectric constants.