I have used the following image files with the results noted.tif -
32bit, 300 dpi, 1811x877 pixels - will not even display, I think it is
too largetif - 24bit, 300 dpi, 359x174 pixels - best quality, but still
fuzzy around curvesjpg - 24bit, 96 dpi, 359x174 pixels - worst quality
of all imagespng - 24bit, 359x174 pixels - fuzzy around curvesgif -
8bit, 359x174 pixels - fuzzy around curves