Q. My PowerPoint slides have a black background. How can I use less ink so I can print on both sides?

It appears that gray-scale and black & white print the same way - background is gray with black lettering. This prints ok double-sided, without too much bleedthrough. Also note: you may have a different outcome depending on the version of PowerPoint you use and whether you are printing as slides or handouts. Students report that handouts print with white background and black lettering when sent to the black & white printer.