I have recently been cleaning a group of marble busts. As I clean the backs, I have been finding black ingrained dribble marks as though dirty water has been pouring down. I have heard this attributed to condensation, but I don't understand how this could have happened as the busts have always been kept in an internal hallway so less likely to be subjected to condensation. Any ideas? ****** Unsubscribe by sending a message to [email protected] Searchable archives: http://cool.conservation-us.org/byform/mailing-lists/cdl/
