Epson Stylus Pro 7700 User Manual page 21

High Print Quality: Print mode
Print Mode for Epson Stylus Pro 9700/7700
1440x1440 dpi mode for line drawing* (Compatible with certain media)
2880x2880 dpi mode for ISV
"sRGB (Epson Standard)" and "Charts and Graphs" mode are available
360x720 dpi mode for the fastest throughput (Plain paper only)
Improved sharpness by providing 1440x1440 dpi mode
720x720 dpi 1440x1440 dpi
See the technical guide for more detailed differences of pictures above.