The cloth that Randolph Herr describes was called Bilon by the people
who used it to cover my Ampico pneumatics, circa 1985.  I don't
remember a distinctive odor; however, it did not last and had to be
replaced about ten years later.

I used this stuff, with white PPCo glue, to rebuild a Baldwin piano in
the early 80s.  Neither were supposed to be any good.  But the piano
still plays perfectly today with no holes or separations.  Why, I don't
know.

Larry Mayo