Since there doesn’t seem to be much of a difference in image quality between the 2880/1440 dpi and the 1440/720 dpi settings on the Epson 3880 driver, I’m confused about why both exist. Having three different ink drop sizes in 1440/720 mode results in print times about half of those printed with the higher-resolution setting, so we wouldn’t want to get rid of that one.
The cynic in me thinks that the 2880/1440 dpi mode is there mostly because it looks good on a data sheet. I’m not saying that the printer can’t position the dots that accurately; I have no reason to doubt that. I’m not saying the dots are too big to take advantage of the highest resolution setting, although at a tad less than 1/1000 of an inch, they’re marginal for the 2880 direction. I am saying that the noise introduced by the halftoning routine obscures any detail finer than what can be rendered at 1440/720, and that the image smoothness of the higher setting is no better than the lower.
In both resolutions, the printer uses only the smallest dot sizes to create tones of Zone VI (or maybe VI and a half) and lighter. Thus the dots are fairly far apart in the near-highlight areas. This situation cries out for an ink even lighter than light light black.