I picked up a used P bass neck that someone did a very sloppy defret job on (you can see where the pried the frets out by the damage on the fingerboard). I don't want to use putty as that will result in some extremely uneven gunky looking lines. I'd strongly prefer some sort of shims. Problem is, I am having difficulty locating material thin enough to fit into the slots. For those of you who've defretted a neck before, where did you find material to fill the slots left over? Suggestions on material other than wood also appreciated.