I used a clear acetate (0.012in.thick) overlay for the buttons. This way, the end user can change legends by printing their own labels on paper using an ink-jet printer. This is one of the nice features of a capacitive switch - you don't have to spend a lot of money for custom labels (and the attendant lead times). And you can change labels easily and cheaply at any time. There is a downside though - there is no feedback (like tactile with a mechanical switch). I implemented an audible click using a buzzer like this one, which is also used for alarms, etc.