Minimum line width and black optical density (KOD) are key image quality attributes for AEC (Architectural Engineering and Construction) and MCAD (Mechanical Computer-Aided Drafting) markets. In the past, it has not been possible to simultaneously optimize line width and black area fill optical density with the same printmode. This has forced users that needed minimum line width to trade off optical density in black area fills, and vice versa. This trade-off is a well known product limitation for many inkjet printers. Further, throughput in these applications is improved by the use of bidirectional printing, however the directional differences in spot shape and placement cause degradation of line and edge quality. This invention gives a new method of processing image data that enables thinner, crisper lines, while maintaining maximum optical density in area fills, with the same fast bidirectional printmode.