Hi John, The old wall dials in France and Italy are often painted using the fresco technique. Here metal oxide pigments, ochre etc, are incorporated into the lime plaster which converts to limestone. They are permanent and last as long as the wall stands subject only to erosion of the limestone. This is why many Zarbula dials still look fresh over 150 years later but are generally they are washed by weathering or obscured by dirt. Chemically the fresco pigments are as stable as glass but lime plaster is softer and more subject to erosion.
Regards, Roger Bailey -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of John Carmichael Sent: April 24, 2007 2:34 PM To: 'Sundial List' Subject: RE: Porcelain Sundials p.s. But I still love the hand painted wall sundials found in France and Italy, even if their paint doesn't last as long. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
