a pre - printing toner - save method for selective , different - character page description language color - object rendering of different - category pdl color objects . this method includes a preliminary determination regarding whether such an object is categorizable as a text object , as a graphics object , or as a raster object , and a subsequent , “ post categorization ” evaluation of whether the specific - category object nominally selected for toner - save treatment possesses a certain preselected threshold characteristic . objects so categorized and “ successfully thresholded ” are then subjected to differentiation into different object regions , and then to toner - save rendering which includes the two , collaborative steps of preserving object - edge dot density , and , within an object &# 39 ; s bounding edge , establishing a checkerboard pattern of dots which maximizes dot gain .