Posted Jan 19, 2012. by Dlward Stock Using Opacity - This is an example of how powerful using opacity with a limited palette can be. The base layer is a black rectangle, with layers of partly- to fully-opaque objects piled on top to create the piano keys. Original photo by me and imbedded in the .ai file. Please mess around with this, move things around, change things. This is for you to learn how to use Illustrator better, giving you a finished version from which to deviate and maybe get some ideas. File Size. 2.5 Mb .zip