118 x 120The area surrounding the app icon must be invisible, not black. if you want to do it the correct way, you can use square icons measuring 120x120 pixels. then, the corners will be rounded automatically.
edit: maybe your source uses the icons on a black wallpaper where you just can't see the black border. the fix would probably be to create new pngs sized 120x120 pixels with an invisible background and then cut out the icon shapes from your source files and paste them into your new invisible png files.
that sounds Iike you were trying to scale an existing image to 120x120. what I meant was that you have to create new files sized 120x120 with the background set to invisible, then cut out the icon shapes from the other files and paste them into the earlier created new files that are 120x120.118 x 120
if i put 120 the second number goes to 122, -_-