Love flat wounds (D'addario or Fender) -- I have 2 basses with "tapewounds" and two with ROUNDWOUNDS -- for the METAL-- Motorhead-- ATTACK type tunes-- the rest are flats-- the majority of my thumping is on flats.....love the flats -- especially on a fretless.......dear Lord its heaven to the fingers....Ive never played an upright bass but I assume its "similar" in feel.
Our bassist (currently) uses a black string that is coated with something. He cleans them periodically with denatured alcohol and keeps using them. He plays quite aggressively too.
We are tracking tonight so I will ask him for the brand name...