I believe pau ferro is actually softer than rosewood (Janka hardness scale) so I'd expect more string marks. MM used it on their Stingray fretless so I have to believe it is a solid choice.
And please, don't bend strings for vibrato on fretless, move your finger slightly along the length of the strings like a violin player does.
Strings? Flats will mark the neck less than rounds. I've been using TI flats on my ebony neck but recently switched to rounds because I wanted more upper clarity from the notes. I expect more marks. On PF I'd take the same approach. Try flats. If you're happy you're done. If not, rounds for the sound.
^THIS^ A whole lot...
- Yes, Pau Ferro
is softer than Rosewood -
REAL Rosewood from the
genus Dalbergia. There is one - just one - species from this
genus that is as "soft" as Pau Ferro. The ones that were/are traditionally used for instruments, are considerably harder. Currently, the fingerboard/fretboard woods that are
called "Rosewood"? They really are not - including "Bolivian Rosewood" - another, specious name for... Pau Ferro....
I have 4 fretless basses, currently. 3 have Ebony fingerboards; the other one? It's a bass from a 1-man company in Canada; every bass/guitar he built is a custom one. It's a 32" scale, '93 Fury Anthem lined fretless. It was specifically made to wear tape wounds (don't ask me how I know), and it was played quite a bit before I got it. Even with tape wounds, the fingerboard is pretty worn - to the point that I'm going to give it to a luthier I know next week, and let him decide whether it needs refinishing - or not. And, whether I should have it epoxy coated...
As for Strings? Any electric bass strings will wear your fingerboard out - eventually. How fast, depends on what kind of strings you decide to use - and, to an equal extent, how you play. So, use whatever fingerboard wood makes you happy - same goes for strings. Just know beforehand, that your choices will have consequences - sooner, or later...
