Al,
I agree with some of the remarks about letraset, although on its own its not hardy enough for the finger wear that occurs around knobs on instrument panels. So it needs a coat of varnish over it improves it. This can be a problem though with painted panels, but its less of a problem with bare metal panels.
Also, the computer laminate method I have tried too, covers large surface areas, which you might not want if you have prepared the panel with some other special finish. So I have moved to labels made by small Brother label machines. Not only do the label tapes come in color, but they are also available in transparent, with white or black writing, and I often cut them down to a small size around the lettering. I've nearly finished building a machine with a red painted case and white writing on it, will post a photo later.
If you look on about page 8 of this article at the Fetron radio, you will see this label material, black on transparent on the IF cans and aluminium can coil covers and gold writing on black tape for the chassis labels. The transparent tape is hard to see, and just the black writing obvious:
http://worldphaco.com/uploads/WORLDFETRON.pdf
For other projects I have my local sign writer engrave the material and fill it with black paint, like the top on this regulator which is 3mm thick aluminium, scroll to the last 2 pages to see a photo of the top:
http://nebula.wsimg.com/16f83c1c70ef...&alloworigin=1