Well, here is what I actually did, once.
I have a 1946 vintage aircraft temp gauge that had faded badly. So I took the scale off the gauge, scanned it with my computer, and then edited the photo to make it darker. Then I printed it out on photo grade paper with a photo grade inkjet printer and glued it over the scale of the gauge. I had to drill out the tiny rivets that held the scale on to be able to remove it and scan it and then found some teeny tiny screws and nuts to put it back on.