The key to have a better looking black background is to make sure that there's no air or dirty stuff between the glass and the background. Unfortunately I realized that all too late - don't have access to the back of most of my tanks anymore.
Here is a nice piece written by Japes on how to do it. I tried it on the last tank I set up and it worked great - http://www.monsterfishkeepers.com/forums/showthread.php?t=236032
Here is a nice piece written by Japes on how to do it. I tried it on the last tank I set up and it worked great - http://www.monsterfishkeepers.com/forums/showthread.php?t=236032