Portable paintings can be divided into easel paintings: that is paintings which were painted on either canvas or a solid support, typically wood; paintings on paper and ivory’ and then there are the immovable paintings on painted on the wall- mural painting as they are known.
Easel paintings consist of the support (the canvas or panel); the preparation layer, the paint itself, which is composed of pigments held in a binding medium such as oil, glue, egg, casein, or acrylic; and, finally, the surface coating, usually a varnish, to protect the paint and modify its appearance aesthetically.
Wood-panel supports were used almost universally in European art in devotional icons and other works before the 16th century, when the use of canvas became dominant. Wood has the disadvantage of swelling and shrinking across the grain when there are variations in the RH of the atmosphere. To counteract deformations of the wood, restorers in the past placed wooden strips called battens, or more complex structures called cradles, across the back of the panel to constraint the movement. This solution, however, often led to severe distortion of the painted surface, causing extensive damage to the paint. Nowadays where possible we advise an environmental approach that places the emphasis on the maintenance of a stable environment that fosters preservation.
Painting on canvas became common in the 16th century. A canvas support expands and contracts with variations in RH and canvas does deteriorates over time. As a result, parts of the paint and ground will lift from the surface of the canvas, suffer cracks and eventually drop off the canvas support and be forever lost. The paint layers themselves are subject to a number of difficulties as a result of natural decay, faulty original technique, unsuitable environmental and hanging conditions, ill treatment, and improper previous restorations which unfortunately were often very aggressive.
Many of the common problems associated with paintings and their frames can be identified with the human eye. Keep an eye on your canvas and panel paintings and frames using a magnifying glass, torch, and take photos to monitor your pieces. Should you notice large changes, it is probable that your paintings need treatment. Nonetheless, at times the painting will not need treatment, even small improvements can make a significant difference for the long-term well-being of paintings and frames in your collection.
Wall paintings are the oldest known form of painting, dating back to the prehistoric paintings such as the Altamira cave in Spain and the Lascaux Grotto in France. The conservation and restoration treatment of two Renaissance masterpieces, Michelangelo’s frescoes in the Sistine Chapel in the Vatican and Leonardo da Vincis Last Supper in Milan, drew the world’s attention to the environmental and structural vulnerabilities of these treasures.
Many refer to wall paintings as frescos however ‘fresco’ is a technique of painting on the wall and many murals around us are not actually painted in fresco technique. Wall paintings are integral to architecture, in both a material and an aesthetic sense. The conservation of wall paintings inevitably concerns not only the paintings themselves but also the larger context the building materials, building maintenance, its use, and its preservation. There are several reasons why these typology of paintings suffer deterioration, and in most of the projects we undertake we work with a multidisciplinary team.