FRESCO

WALL PREPARATION

After having cleaned the whole wall (all previous plaster or traces of cement must be removed) the first layer of mortar, consisting of a mix of sand and lime, (spenta) is laid. This first layer is called "arriccio" roughcast because it must not be flattened or smoothed so that the next layer will have a better adherence. It is possible to add some marble powder to the second layer and this can be more or less smoothed according to the artist's preferences. Before this operation it is possible to insert an intermediate coloured layer which permits the use of graffiti, incising with a pointed instrument or any other tool as required.

THE COLOURS

Natural colours must be used, clay and oxides or pure pigment suitable for fresco and diluted in water. The process takes from 5 to 8 hours, depending upon the environment's temperature and the wall's absorption capacity until the plaster is able to soak up the colours which would otherwise remain on the surface and therefore be destined to disappear after a short period of time. Obviously within these strict rules the artist's sensibility is essential in the interpretation of the technique with all the possibilities which he can offer, as is the case with incision and lithography.

It is also possible to create a fresco on a mobile support however it must be able to support the weight of the plaster. The simplest to construct consists of a metal frame which holds a galvanised metal net or other material available from the building industry. When large surfaces are involved the working area is divided into portions which can be painted within five hours and take the name "giornata" (day's work).

Translated by Jane Rusconi, October 2002

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