So... is putting these things on your guitar generally a bad idea?
I mean, is there any objective reason why it's not a good thing to do or is it just it may look the guitar look ugly/etc?

And, while we're on the topic... What's the best way to mark the frets on a guitar? (Solid Rosewood fingerboard)

Basically, my guitar only came with 3, 5 and 7 marked on the "top" side of the neck. Since I didn't want to touch the fingerboard itself, I small dots along the same side of the neck using some liquid paper I had around. That worked fine for a while but it's pretty much coming off from the frequent contact with my hands.

Does anybody have a better (and hopefully more elegant) solution for this?