I originally created this single graphic element in vector format and rasterized it as a 2" bitmap at both 720 ppi and 360 ppi.
The 360 ppi image was resized in Photoshop to 720 ppi using 'nearest neighbor' resampling to preserve the crisp 'stair-stepping' and avoiding any antialiasing in the conversion process then composited to the 720 graphic.

If you copy this image to your computer, make sure you are viewing at the original size here on PBase and upon opening in a graphics editor it should be 2880x1440 pixels and 720 ppi.
If it is NOT at 720 ppi the file should be changed by NOT resampling the image.

The purpose of this image is not to prove that the native resolution of Epson printers is 720 ppi but rather to prove that with many Epson printers, the native resolution is higher than 360 ppi.
It invariably will be 360 ppi for many of the older Epson Pro printers. (Edit 050620: It is doubtful at this date that any of those old Epson Pro printers are now being used)