I#ve recently re-washered the H & C taps on the
bathroom handbasin.

Now, both washers were from the same batch, but
whereas that on the cold tap remains soft (and
requiring more and more turns to shut it off),
that on the hot tap has gone hard and seems to
be dripping again unless screwed down hard.

I suspect that the hot tap needs reseating,
but it there any explanation for the differing
performance between the H & C?