I went to create 9 maps for the achievement and I found all my maps (both with and without a compass) were revealing the whole map image when I created them. I thought it would maybe still work when I tried to put them on the wall but it did not trigger.
The problem is I have no idea what parts I still need to explore so it's near impossible for me to fill them out.
I also noticed all my maps had different levels of lighting when I put them in the wall and I don't know if that's an indicator of anything.
Are you saying crafting does not result in an object called "Empty Map"? If you use an empty map near the center of a chunk, the size of the map is so small that everything in it is immediately explored. Only activating them near a corner of a chunk will leave the other corner unexplored. When you zoom them out (which wipes out all map data, including the parts you have already explored), you can see it being explored more gradually.
The light level depends on the level of lighting on the block, in your screenshot you can see the maps closer to torches are brighter, and furthest away from the torches (top and bottom) are darkest.
Also, I believe the 3x3 map achievement is still broken.