Eric Luis,
Thank you so much for your advice. It turned out that
those gray lines where indeed caused by the antialias
parameter of ghostscript. I found out that the
Helvetica font probably gives the best readable results
on low resolution.
So here's what I managed to achieve:
Dear ABC friends,
...And now for something completely different!
When abcm2ps creates its postscript output, it shades
the staff lines by adding tiny gray lines beneath the
black lines. This looks wonderful when you print the
output, but unfortunately it doesn't look as nice when
you convert the
