A toner for developing an electrostatic image, a developer for developing an electrostatic image, a process for producing them, and a process for forming an image that provide excellent developing and transferring performance and also provide excellent performance stability, as well as high image quality and reliability are provided. The semiconductor layer is electrically isolated from the first electrode. The database is used to store font data of a plurality of characters. The bowl is formed by multiple flat panels folded to surround the screen. Filter assemblies and filtration systems incorporating such fabric.