The low precision of the printing device (printing quality).
Set maximum printing precision (printing quality) (Start \ Setting \ Printers \ File \ Properties \ Graphics \ Permission).
At low support by the device driver of the graphic palette installation functions the printed image is represented by pure colors (without taking into account shades).
Try to replace the printing device driver by its new version (if you have this possibility). Perhaps the new printing device driver has the best realization of the output functions onto the printer.
Try printing in other Windows version (if you have this possibility). There are different driver sets are used for different versions of Windows systems (98,NT,2000,XP). Perhaps the printing device driver for the other Windows version has the best realization of the output functions onto the printer.
If the image has raster line rarefaction, or the image is filled completely by black color, or the image is divided on the unmatched raster strips, the incorrect printing device driver adjustment or low support of the 24-bit raster image output by the printing device driver may be their reasons.
