1220C 4X6 Printing

I'm attempting to print on HP 4x6 Photo Paper with tab on a
DeskJet1220c connected to a Mac running OSX (1.3.5), using either the
HP (2.51) driver or the CUPS driver.

Since the printer won't print borderless I'm attempting to center the
image on the page so that I have even borders.

There is no page size in the page setup dialogue to match this paper so
I have tried custom sizing or the 4x6 card size.

Neither seem to produce consistant results.

Could someone (Yo Bob), perhaps give me some hints or point me in the
right direction?

TIA

G