This invention concerns an electrophotographic printing apparatus comprising an image-forming member having a surface on which a latent electrostatic image can be formed, a developer for depositing onto the surface of the image-forming member a layer of ink, the ink comprising charged ink particles and a carrier mediums a supply conduit connectable to an ink tank for supplying ink to the developer and an exit conduit connectable to the ink tank for delivering unused ink from the developer to the ink tank, the supply conduit, developer and exit conduit defining a flow path and a separator for separating the carrier medium from the ink particles, the separator connectable to the flow path to receive unused ink and to reintroduce carrier medium extracted from the unused ink to the flow path.