Abstract: A method of producing a color toner whereby a binder resin, a chromatic coloring material and a metal oxide particulate material are mixed to obtain a first mixture. Thereafter, a second mixture is obtained by mixing the first mixture with a material other than the materials used to obtain the first mixture. The second mixture is melted, kneaded, cooled and pulverized.

Abstract: A sealing member for a developer supply container in the form of a two-sided tape constructed of adhesive layers attached to the opposite sides of a substrate with adhesive. A thin film member is attached to one of the adhesive layers. The other adhesive layer is attached to the periphery of an aperture of a developer supply container to seal the aperture. The strength of the substrate is less than the adhesive strength of the adhesive layers relative to the film member and the developer supply container. When the developer supply container is placed in an image forming apparatus, the aperture is opened by pulling the film member. As a result, the film member is peeled from the developer supply container and part of the substrate is removed from both adhesive layers along a layer surface of the tape, with one side of the separated substrate remaining attached to the periphery of the aperture of the developer supply container and the other side of the separated substrate being pulled out with the film member.