We have a beautiful Indian Peacock slate corridor in the school I'm at.
Over time the sealer has worn away in some places and underneath is
dull and lacks the original pattern.

I wonder if it might be possible to "touch up" that slate which has
been revealed - we tried different shades of shoe polish, that did not
work. It wouldn't stick to the slate.
But what about oil paints or something else.

If we succeed witht the touch up, we will seal it again and it will be
good for a few more years.

Mike