Change launchpad folder background wallpaper osx lion / mountanin lion

This will show you how to change the background wallpaper of the folders in launchpad in osx lion and mountain lion.

open finder
goto /System/Library/CoreServices/Dock.app/Contents/Resources
find the file ecsb_background_tile.png
rename it to ecsb_background_tile_backup.png
copy the image that you want for the background of the launchpad folders to the folder and name it ecsb_background_tile.png
open terminal and type
```
killall Dock
```

now your folders in launchpad will have a new background