Quote: Tony, correct me if I am wrong, but (for Epson) as long as the print resolution is 1440 divided by an integer, it will not interpolate to 360. And in particular 180 and 240 ppi should be fine as well (i.e., no additional interpolation when sent to printer).
I can only state what my opinion is based on my own observations and others more expert opinion plus Epsons own recommendations.
I believe the current thinking is to resize and resample to the native resolution of the output device in your application of choice and then apply output sharpening. Doing this will ensure optimal quality.
Knowing the native resolution is also helpful determining the amount of output sharpening to apply - higher radius (up to double!) for 720 ppi than 360 ppi
The nozzle spacing of Epson print heads has a native resolution of 360 dpi **. Therefore any image that is exactly 360 ppi or direct multiples or half should produce an image without jaggies and the best sharpness.
The print output resolutions are direct multiples or half of 360 dpi e.g. 180 dpi, 360 dpi, 720 dpi, 1440 dpi and 2880 dpi.
The printer will spool your image data and resample to its native ppi - if that ppi is less than printer native it will resample to its native size using its internal algorithms which may be less than optimal
**My Epson P800 nozzle spacing equates to 180 dpi (or should that read npi -Nozzles Per Inch
). I believe it likely that the declared resolution is still 360 and that micro stepping of the paper achieves the 360 or multiples or that it is simply resampled to its declared resolution