Terminator is a great terminal, but running compiz it might be a bit confusing getting real transparency (if you’re one of those). With reference to the terminator man page (man 5 terminator_config), edit ~/.config/terminator/config and add these lines:
enable_real_transparency = true background_darkness = 0.7 background_type = transparent
Note: use background_darkness to adjust the level of transparency 🙂