spacing in gtkbutton

[timf <timf trdlnk com>]

i have an application which has a vbox of buttons.  the more buttons i can fit 
on the display, the better, so i would like to shrink the overall height of 
each button by removing most of the space that currently exists between the 
top and bottom of the label within, and the top and bottom of the button.  
looking in gtkbutton.c, i see that there is no padding allocated, is there 
any other setting i can use to achieve this?

thanks!
-tim