Fresco Secco
May 9, 2009
It is a matter of (pretty) common knowledge that one cannot paint on a finished fresco – and hope that it will last. There are many examples of old frescos, now sadly peeling. Therefore, if you must paint secco, take my information, as word of mouth – from a professional. A professor from the Royal Academy of Art in Antwerp gave me this recipe. After five years, the secco painting still looks fine.
The Size:
Pour 80 ml of methyl ethyl alcohol into a chemist’s beaker. Fill it up to 100 ml with 20 ml of Artist’s grade Shellac. Stir a bit. The size is now ready to use. Paint a coat of it over the surface of the fresco on which you wish to work. It is dry and ready for paint in one half hour.
Painting:
The sealed surface is now ready for paint. Pigments mixed in water can no longer merge with the plaster for permanency, therefore, a medium is necessary. Casein, oil or egg tempera? I have read that Casein has been traditionally used, also oil, however I preferred to use egg tempera. This worked just fine.