Hi Anonymous Monk,
I am using GD::Graph::linespoints
I am using following
$mygraph->set_title_font(GD::gdGiantFont);
$mygraph->set_x_label_font(GD::gdLargeFont);
$mygraph->set_y_label_font(GD::gdLargeFont);
It works and changes the font for title and labels for me.
~Rakhee