Atelierartisanal's Blog

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.