As we’ve learned above, there are three resolutions available: 300dpi, 600dpi and 1200dpi. Here is the same test image printed at different resolutions (from the lowest to the highest):
Note that the 1200dpi (HQ) mode does provide more detail but with some artifacts like the merging together of the smallest objects (but at 600dpi they are not printed at all). Slanting lines look somewhat jagged in the 300dpi printout.
The next scans illustrate the printer’s reproduction of black-and-white images and halftones:
A rude and regular dot matrix is perfectly visible in the 300dpi print up to the maximum fill density. The image details are lost and the transitions between the plates of the grayscale become sharp. Black and gray symbols are fuzzy and not very legible.
The 600dpi print is much better: the dot matrix is still regular, but less conspicuous. The transitions between the halftones are not as abrupt as in the 300dpi print. The disadvantages of this mode are that there are visible dots in the light areas and that the darkest halftones all blend into one color.
When the Improve Pattern Printing setting is turned on in the driver, the printer seems to produce better-quality black-and-white photographs. In this mode halftones are reproduced in a different way: the matrix consists of equidistant variable-size dots. The image becomes denser and the transitions between the halftone plates are smoother, but some details are lost in the darkest areas of the image.
So you should use the Improve Gray Printing option to print diagrams and charts (for more contrast between solid fills), while black-and-white photographs are going to look better when printed in the Improve Pattern Printing mode (halftone transitions are smoother).