Printing Question - Rephrased

[kevin at stallibrass.com]

Len, 
I'm a real newbee to programming but work in digital imaging and offer the
following which won't fully answer your question but will hopefully clear a
couple of the clouds...
1.Printerdrivers report resolution changes in DPI settings. This is
tecnically correct -dot per inch
2.Images report resolution as DPI wich is incorrect - it should really be
PPI (pixels per inch)
3.There is not nececarily a mathematical link between PPI and DPI to govern
all printers as each printer driver will use different screens or dither
patterns to achive the dot image, and may not print at 100% 4.Selecting
different printing resolutions in the printer driver will  keep the print
size the same as this instruction is interpreted by most drivers as "slow
down the printer and use finer dots, more closely spaced" - blame the
marketing men for that one! At least that means that trial and error will
not be upset by a change in printer "resolution"
 
Kevin S