Printing JPanel - Sizing output 1

[JamesGordon]

I have a derived JPanel that displays circles, lines etc.
All well and good onto the screen as the sizing doesn't matter, I just use the width/height whatever is the smallest.
My problems come when I want to print.
I need the output to be 6".
If I fix the pixels at 350 the image comes out a different size dependant upon the printer.
How can I get the DPI of the printer and calculate the pixels I need to print to get my 6" print?

Regards,

James.

 

[sedj]

This may help

http://www.javaworld.com/javaworld/jw-12-2000/jw-1201-print-p2.html