There is a Compatibility setting to "Print colors as black on noncolor
printers." This is found at Office Button | Word Options | Advanced: Layout
Options (at the very bottom). I'm not sure whether it also prints in
greyscale on color printers or not (it's not clear how Word knows whether
it's printing to a color or monochrome printer). There's also a Print option
(also on the Advanced tab) to "Use draft quality," but this may go farther
than you want.
And there should also, as JoAnn says, be a setting in the printer
Properties, to print in monochrome.
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Suzanne S. Barnhill
Microsoft MVP (Word)
Words into Type
Fairhope, Alabama USA
http://word.mvps.org