For years imaging scientists have known how to enhance the edges of text and artwork objects, reducing the artifact of "aliasing", also referred to as "the jaggies", along the edges of text and graphic objects. Anti-aliasing of a rendered, continuous tone image fills in the in-between jumps at the edges with pixels having in-between tone values. This gives text and artwork the appearance of smoothness usually obtained only when printing at higher resolutions.
ScaleAbilities has developed a form of text and artwork enhancement, similar to traditional anti-aliasing, designed specifically
for graylevel printing, and which works together with multilevel screening and is optimized for hardware-based acceleration. See it here -->