A carrier for an electrophotographic developer which is used as an electrophotographic developer in a mixture with a toner and which secures sufficiently the image density and can maintain high-quality images for a long period, and an electrophotographic developer using the carrier, are provided. A resin-filled ferrite carrier for electrophotographic developer obtained by filling, with a resin, avoid of a porous ferrite core whose void continues from the surface to reach the interior of the core, the carrier comprising a plurality of three-dimensional laminate structures in which resin layers and ferrite layers are alternately present, and an electrophotographic developer including the carrier and a toner, are employed.

A black film useful in thermal control has a matrix with 100 parts by weight of a polymer, and from about 1 to about 6 parts by weight of an electrically conductive carbon pigment having a porous, sponge-like structure dispersed through the matrix. The film may be a freestanding film, typically about 0.001 to about 0.003 inches thick, used as a radome. The film may instead be a liquid paint or a solid paint applied to a surface.

A coated carrier having a core particle coated with a mixture of an electronegative insulating polymer comprising a polyvinylidenefluoride polymer or copolymer and an electropositive conductive polymer comprising a polymethyl methacrylate polymer or copolymer with a conductive material dispersed therein is made by powder coating. The coated carrier has unique properties, including a conductivity of from 1.1.times.10.sup.-14 to 1.0.times.10.sup.-8 mho-cm.sup.-1, a triboelectric charging value of from 12 to 20 and an average particle diameter of from 65 to 75, rendering the coated carrier ideal for use in a developer to be used in a magnetic brush type development apparatus. The powder coating method includes mixing the core particle and the mixture of negatively charging polymer and conductive polymer until the mixture of negatively charging polymer and conductive polymer adheres to the core particle, heating the mixture of the core particle and the mixture of negatively charging polymer and conductive polymer until the mixture of negatively charging polymer and conductive polymer melts and fuses to the core particle, and cooling the coated core obtained.

Carrier comprised of a core, a polymer coating, and wherein said coating contains a mixture of an alkali metal lauryl sulfate and a conductive component.

Carrier comprised of a core, a polymer coating, and wherein said coating contains a conductive polypyrrole contained in a carbon black matrix; or a polyaniline contained in a carbon black matrix.