One quick label method, once you have your graphic layout, is to print it on overhead transparency film and bond the the whole thing to the panel with 3M #77 spray art adhesive. The #77 isn't totally transparent, so it gives sort of a pebbly appearance to the background aluminum. The layout for this (attached) was done in Autodesk's QuickCAD.
The smooth surface allows easy clean off of finger smudges, and I haven't had a situation where the printing wore off...yet. If your graphics program would allow reversing the graphic, you could have the toner on the protected, panel side of the film.
Ken.