Hello all and black mold on piano catches question

[Dave Nereson]

It's not just Baldwin.  In Baldwins, I've seen the black fuzz from catchers that somehow produce the stuff in their friction with the backchecks and it ends up all over the tops of the catchers and backchecks and down on the regulating rail.  It looks like buckskin that's been dyed black.  But in some Kawai
  verticals, usually studios and some consoles  (60's?, 70's?), I've seen the same thing, but it's tan or yellow instead of black.  There's something about the "grain" or texture or the way the buckskin is split or skived or whatever (I don't know the proper leather terms) that makes it fuzz up.  I seem to remember seeing the same thing in some Asian grands, on the backchecks.  In all cases, though, there's still been plenty of leather left on the catchers or backchecks, i.e., just a little buckskin produces a whole lotta fuzz.
  I've vacuumed a few, but haven't been back to the same pianos (transient customers) to see if they fuzzed up again.  --David Nereson, RPT