People i just discovered why i couldnt get true blacks on my cintiqs, or other monitors, blaming led technology. But envidia was the problem at fault.
Color value are from 0 to 255, i mean from black to white, thats good for photoedition, but real bad for games.
Nvidia cards were built for been in video games, so they dont use those values, they use from 16- 235, so you are skipping the most crucial colors for coloring, but for editing it will SUCK.
So i had found a great web page, with a little software for pc users, that you run it and restart and you get solid blacks, this had made my callibration so easy, it was the graphic card the problem.
Just download the program, unzip it, execute it, and choose from 1 to 255 values, restart and its done.
If you dont like it you can revert it by clicking again the other option.
Corel painter works incredible with those values. You notice this more if you have your monitor connected in hdmi mode.