Oil painting on stone : a case study on original technique and deterioration of an early 20th century painting by Giuseppe Calì in Malta

Abstract

Maltese wall paintings from the Baroque period onwards were mostly executed in oil or oil-based media applied directly to local limestone (Globigerina Limestone), which is a soft, very porous stone (porosity ~ 40%). These murals are often found in a poor state of conservation. One such painting on a dome of a church located near Malta's main harbour was chosen as a case study. · Painted in 1903 and heavily restored in 1963, the painting's advanced state of deterioration makes it an excellent example to review/examine and understand the most common effects and processes of deterioration related to similar wall paintings, and thus to provide essential infonnation for establishing a proper conservation strategy.