Hi Mack,
PPI in strict terms only applies to a visible image, either on screen or a print. An image on it's own, in reality does not anything "per inch", just pixels. Cameras and some software does tag images with a ppi but it's a notional number.
DPI refers to the printer Dots or spray pattern of the printer head and these days can up to numbers in 1000's.
However, a printer has a "Native" resolution, typically for Epson 720ppi, HP & Canon 600ppi.
THE clever feature of Qimage is that it it sends the image to the printer at that print resolution, interpolated by Mike's superior algorithms, so the printer driver does not have to mess around with the pixels at all, hence the excellent prints from Qimage. See
http://www.ddisoftware.com/qimage-u/tech-prt.htmSort of very odd numbers too (607, 303, 202, 151 PPI) unless that is the true printer resolution?
Yes it is but they are odd numbers because you have borderless set in the driver - Qimage reports these numbers from the driver. When in borderless mode, the driver expands the print area by increasing the PPI.
See the Learning Video that covers this:
http://www.youtube.com/watch_popup?v=gMzUxDP_JwM&vq=hd720Terry
PS. Fred beat me to it but our answers are complimentary