IntroductionAlthough filling and painting are distinct procedures, they can be considered highly related processes. They both contribute to the overall integrity of a treated paint. A simple definition of filling, in terms of painting conservation, is the process of "sealing damage to an image layer by inserting a putty, consisting of a smoothed or structured substance" (Nicolaus, 1999, p. 235), while a filler is a “material used to replace missing areas of loss, usually in the base layer” (The Fine Arts Conservancy, 2006). Additionally, in-painting – usually called retouching as an alternative term – can be defined as “a restoration process aimed at cosmetically restoring color and/or detail losses in the paint layer; usually made with a pigment in a suitable binder applied with a brush” (ibid). Nevertheless, one can find notable limitations to the use of the term in-painting in most of the literature, while retouching is, until now, very common. Historical Notes Regarding the conservation of the paintings, the process of filling and in-painting/retouching has not been carried out until recently. For example, according to Conti (2007, p.187), "five large 15th century canvases" were preserved "at the School of San Giovanni Evangelista" by an Italian restorer called Giuseppe Bertani, who wrote on June 1, 1784 a note on his treatment procedure where he clearly mentioned filling as a step undertaken and surprisingly mentioned that painting inside was more favorable than over-painting (retouching), explaining his predilection for "using the brush only there where strictly necessary. This early awareness of what is now called minimal intervention in filling the middle of paper......://www.jstor.org/stable/1505006 (Accessed January 28, 2010). Saunders ,D. (2000) “Retouching: color vision and optical considerations”, in Retouching & Filling. London: Association of British Picture Restorers, pp. 3-9. Staniforth, S. (1985) “Retouching and color matching: The Restorer and Metamerism”, Studies in Conservation, 30 (3), pp. Online]. Available at: http://www.jstor.org/stable/1505925 (Accessed September 27, 2009). Tetlow, A. (2007) “Retouching Complex Surfaces”, The Picture Restorer, 32 (fall), pp. 5 -10. Author unknown. (1830) Recreations in science. Google Books [Online]. Available at: http://books.google.co.uk/books?id=Z9JnypuNwW0C&dq=recreations+science&source=gbs_navlinks_s (Accessed: February 15, 2010). Wehlte, K. (1975) The materials and techniques of painting. Translated by Dix, U. New York: Van Nostrand Reinhold