An image forming apparatus corrects a development contrast for normal image formation so as to satisfy the following relationships:VcontG2=VcontG1\xd7VcontP2VcontP1\xd7\u03b1, and0. A system comprises a host application executing on, for example, a personal computer, and one or more networked devices executing a client application. The loop member includes a bend causing the loop member to extend away from the pipe, the loop member being flexible enough to accommodate a movement between the open ends of the pipe.