How to adjust output for printer resolution?

I'm trying to print a report using Delphi 3 Professional, but without
using a report package such as Quick Report... I'm simply using
Printer.Canvas.Textout() to draw on the page.  

The problem (question) is -- the report works well when I set the
printer to 360x360 dpi resolution, but at 720x720 the output is a real
mess.  Since I can't rely on the user to set the resolution to what I
expect, obviously I must check the printer parameters and adjust
accordingly.  How?  I know how to use GetDeviceCaps, but I can't
figure out which values to use and how to apply them.  Am I missing
something simple?

Thanks,
Bob Hilton