Output positioning options used by Gimp when printing to CUPS

[raccarva]

I am trying to figure out what CUPS (or would it be lpd/lpr?) printing options Gimp uses to set the output position when you print an image.
When you set the Left/Top fields in the "Position" print dialog tab, I guess Gimp uses some job printing options through CUPS/lpd/lpr to adjust the output image on the media. 
I need this information so that I can try to print images (outside Gimp) in the same position regardless of the printer being used.

Does anyone have this information?

Thanks.