A printing technique wherein pixel locations that are requested to be
marked with only black are identified, black is applied to the identified
pixel locations, and non-black color is applied to those identified pixel
locations that (A) have an associated black half-tone threshold level that
is darker than a predetermined non-white threshold level, and (B)
correspond to on-pixels of a reference pattern of non-black color pixels
having an on-pixel population of at least 20 percent and a toner transfer
efficiency of less than about 20 percent.
