Epson Stylus Pro 4000 Product Support Bulletin page 8

4. From the "Print Settings" menu Continue with other settings, such as like
Media Type, and Print Quality settings.
To obtain the best image quality select a resolution of
TIP
1440 or higher with High Speed unchecked. The finest
detail selection renders at 720dpi instead of 360dpi and
will reduce the maximum page length to 41.66" vs 83.3"
EPSON Professional Graphics Group Page 4 of 8.