When I had my Curbow 4 fretless I tried the LaBella deep talkin flat wounds and was suprised at how well the sounded when I slapped em. Other than that I have moved on to the TI's. But you could also try DR lo riders. They sound good..At least to me.
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I wish I had a collection worth sharing pics of.
I wish I was a little bit taller.
I wish I was a baller....
5 String Club #20