Controlling Screens on PostScript Printers

You can control the screening of a rule, line, or graphic object frame, of the interior fill of a graphic object or text block, of text itself, of a gradient, or of a grey-level TIFF image.You can set the screening parameters to be document-wide screening parameters, or you can override the document-wide screening parameters on a case by case basis. One option for the document wide screening parameters is to use the printer's built in default values.