My brother used to work for Epson (back when the Stylus Photo and the 1720 were just being introduced). At 1440x720, printing an image at 150dpi and 300dpi had no visible difference at all (to the naked eye or under a magnifying lens) because of the droplet size. 300dpi was mostly for dye sublimation printing. With the 2880 and the newer smaller droplets on models that came after the photo and 400/600/800 series, though, I'm not sure. - darkpen