Deteriorate sound quality, I don't think so, inlay materials are extremely thin, you are not going to remove much wood, look at a Les Paul fretboard, they may be kind of plain, design wise, but thats alot of inlay, alot of ultra high-end accoustics have are really overboard with inlay, if it affected sound quality, I don't think you would see it used much....... of course some people swear they can hear all kinds of stuff, I'd like to administer some blindfolded tests before I start believing some of their claims.....Hmmm, sounds like a pink tele, with a gold plated bridge, Ernie Ball strings, .009-.042, changed 3 days ago, the guitarist is wearing green socks.........