What is a non-hazardous method to remove the letters from keyboard keys without introducing a non-smooth texture?

I need to remove the letters and numbers from the keys on a number of keyboards. This needs to be done in a non-hazardous fashion without introduction extra physical textures on the keys.

The keys are standard plastic keys on Microsoft keyboards.


das keyboard ultimate
(source: daskeyboard.com)

Das Keyboard Ultimate - no key inscriptions


This site also sells blank keyboards (and in 90's web style!) for ~$50. They also sell blank key overlays, so maybe you could just cover over the keys instead of removing the ink?