Try recording a macro

If you like using a background to reduce the glare, but you don't like changing your settings throughout Windows, then create a macro that adds stationery and then create a macro that removes the stationery. Click the macro just before closing and sending to your client.

You might also find a theme in Word that you like that will apply a background and text color in one fell swoop and then remove the theme (or apply a "plain" theme) before you close and send to the client.

Just throwing out ideas :-)