BCD 2018

164 C AT H E D R A L COMMU N C I AT I O N S C E L E B R AT I N G T W E N T Y F I V E Y E A R S O F T H E B U I L D I N G CO N S E R VAT I O N D I R E C TO R Y 1 9 9 3 – 2 0 1 8 Graphic programs and visualisation may be useful when presenting spot uncovering results and potential representation options to the architect and client, Chapel of the Sacred Heart, Roehampton paint layers and their substrate, environmental conditions within the building, and also the size of the area to be consolidated. Surface cleaning typically addresses loosely bound dust and more embedded grime, carbon-based residues, nicotine and other pollutants associated with people and animals. Other accretions which require removal from wall paintings include microorganisms, plants, insects and related residue, salt efflorescence and crusts. Later coatings such as varnishes, overpaints and plaster or cement may be removed from the surface where justified. However, the purpose of such interventions must be clear, and the integrity of the original painting should be prioritised over aesthetic considerations. Cleaning may involve dry and wet methods, including water-based solutions and organic solvents of varying polarity. The use of gels and poultices may be needed to achieve a satisfactory result, particularly for varnish and overpaint removal, or if preservation of the surface patina is of concern. Overpaint may be removed partially or fully for reasons of historic and scientific interest, recording or education, but it always needs to be supported by research indicating that it will not be at the expense of damage to overlying decorations, which may be of significance. Thorough research and testing should always precede the works and assumptions should never be based on the results of a similar project. Retouching may or may not be included in the remedial works and it is mainly considered in the aesthetic categories. It is frequently undertaken to improve the legibility of the design and its clarity for the public or owner’s appreciation. Generally, retouching which is discernible at close range and aesthetically satisfying from a distance appears to be a successful compromise. Suitable techniques include: graphic methods utilising points ( pointilisme ) or vertical brush strokes ( tratteggio or rigatini ); methods employing neutral colour field or aqua sporca (‘dirty water’, obtained with diluted watercolours); retouching on fills lower than the surrounding surface ( sotto livello ); on a foreign substrate material not fixed permanently to the painting; or by the addition of phosphors easily discernible in UV light. Purely mimetic methods of retouching (facsimile retouching) are the least suitable from an ethical point of view, but may be justified for aesthetic reasons. In any case, retouching should be limited to the areas of repair and complete loss of paint layers. The selection of remedial treatments presented above is generally applicable to paintings executed in various techniques on a plaster substrate. THE IMPORTANCE OF LIAISON The conservator is rarely the only person involved in treatment of a wall painting. Most conservation projects involve a team of specialists and consultants, and effective liaison and open dialogue between all parties are the best warrants of success all round, including meeting deadlines and financial targets. In this process the role of conservation architects cannot be overestimated because, due to contractual restraints, they are frequently the link between the conservator and the owner/client, and their interpretation of the conservator’s intention based on thorough knowledge and experience is in the best interest of the treated object. Further Information P D’Armada and E Hirst, ‘Nano-Lime for Consolidation of Plaster and Stone’, Journal of Architectural Conservation , Vol 18, No 1, 2012 B Biçer-Şimşir et al, ‘Lime-based Injection Grouts for the Conservation of Architectural Surfaces’, Reviews in Conservation , Vol 10, 2009 Cather S (ed), The Conservation of Wall Paintings , Symposium Proceedings, Courtauld Institute of Art and Getty Conservation Institute, London, 1991 R Gowing and A Heritage (eds), Conserving the Painted Past: Developing Approaches to Wall Painting Conservation , EH Conference Post-prints, London, 2003 R Gowing and R Pender (ed), All Manner of Murals: The History, Techniques and Conservation of Secular Wall Paintings , English Heritage, London, 2007 Historic England, Nanolime: A Practical Guide to its Use for Consolidating Weathered Limestone , HE Technical Advice Note, 2017 U Lindborg (ed), Conservation of Mural Paintings , National Heritage Board, Stockholm, 2001 P Mora et al, Conservation of Wall Paintings , Butterworths, 1984 LUCY KASZEWSKA studied conservation of paintings and polychrome sculpture at Nicolaus Copernicus University in Torun, Poland. She works as a senior conservator at Hirst Conservation Ltd, where she is involved in the development of conservation strategies, undertaking and supervising treatment of wall paintings and decorated architectural surfaces.