ha..ha..ha... very good viol8ion... I read right over the "psi" and didn't even see it...quite right of course (sorry cartix, no offence intended)
My "dpi" reference is just an old habit from having used PS for so long... back when images were used *only* for printing...before anybody thought of putting them on web sites <grin>. You're right of course, that a file is made up of 'pixels' not 'dots' and should therfore be referenced as 'ppi', but since cartix was asking about printing the file, well.....
and Yes 'dpi' does refer to screen display, but any print shop will tell you that their presses are in fact printing 'dots' and not 'pixels' so they always refer to file resolution as dpi (right or wrong). Suffice to say that a 300ppi file to PS, is a 300dpi file to a printer.
Bottomline (after all my rambling) is; Sorry, Cartix, you're not likely to be very happy trying to blowup a 1x1.5 file to 10x8... at 150ppi, dpi or even psi <grin>...