I decided to paint my keycaps for fun on an old Kinesis keyboard. After doing the keycaps I did a lighting mod on it later which I just posted here:
http://geekhack.org/index.php?topic=45078.msg939339#msg939339Here at the finished keycaps. The letters do not show through as much as the photos show them you can barely see them. I'm fairly happy with them.
This is more of a "What I did" not a "how to" because I just did what I wanted.
So the first thing I figured out was extremely helpful.
You need these toothpicks. They fit perfectly in the keycaps and hold them tight. Then you just put them in some cardboard and you have an easy way to get full coverage of the keycaps and not have them touch the ground. Plus your out only $2-3.
I used this paint from walmart.
It took two coats to look perfect all over with an hour between coats. You can see the letters underneath in the photos but you can not really seem them in real life unless you have a light hit it perfectly. For some reason the spherical keys looked the worst after only one coat. I don't know exactly why maybe it was because they were blue to start with.
I also painted the case which was originally white. It was much harder to do and get even. I think it was because it was older but it was hard with all the curved surfaces to get the paint even. Plus I scratched the crap out of it and messed it up in several places while doing my other mod so I would need to repaint it to look right.