How do I overlay two similar maps on top of each other
If you're trying to do this in Word, that's possibly the worst
possible choice (except maybe Notepad).
Use a graphics program that can handle multiple layers, set the
transparency of each layer independently, and then flatten the layers
into one for export as a graphic file.
The classic of this class of program is Adobe PhotoShop, but there are
free alternatives at
www.getpaint.net and
www.gimp.org.
