size of plot area

[Jim Benedict]

GrADS users,

Does anyone know how to make a plot (e.g., gridded OLR on a global map) that is exactly 2400 x 1200 pixels?  I've tried 'printim filename.png x2400 y1200 black' but for some reason these pixel dimensions also include a ~110 pixel black-space border on each side.  I need the plot area (that is, the global map itself) to be exactly 2400 x 1200 pixels with no border.  My plot does not have axis labels ('set xlab off' and 'set ylab off') or any text or color bars outside the map area.  I've tinkered with 'set xsize' and 'set parea', as well as scaling and not scaling the map projection, but I cannot find a configuration that works.

Thanks for any help!
Jim