To clarify that... Printing dpi has to do with density and extrapolation . 150 dpi is more than adequate for printing information. the printer will fill in the rest. We can't really prercive anything above 300 with the naked eye. Whereas slynky's method merrits, it's not nessacary if you know what size you want to print at. But it's good to leave your options open. A greater dpi will allow to to enlage without pixelation.