ABSTRACT. The aim of this paper is to reshed some light on the broad subject of cleaning from the viewpoint of a museum conservator. One of the main reasons for cleaning or removing the varnish of a painting is a planned exhibition. This is surely not the most convincing reason for an intervention and can lead to more frequent restorations than necessary or desirable, often the fate of famous works of art. These actions are arguably the most controversial and dangerous restoration interventions that a painting will face. Such interventions are diffcult because, on the one hand, the painting should not be touched if at all possible but, on the other hand, it is often unavoidable that work must be conducted directly on the painting. This means that the intervention, the effect of solvents, and any contact should stop exactly where the original paint layers begin. This cannot be guaranteed, either by traditional means or with modern materials and methods. The cleaning of a painting is more than a great physical risk for the work of art; under certain conditions it can also cause signifcant changes in its aesthetic appearance and perception. The success of an intervention, in particular, that of cleaning a work of art, thus depends on the cooperation between practitioners, art historians, and scientists, a partnership that is not always free of confict. Relationships, historical facts, and questions of meaning must be collected and taken into account. This paper is intended to examine and enlighten the full range of issues encountered by professionals involved in the restora- tion of paintings, with particular emphasis on conservation ethics and the genesis of conservation treatment decisions. PRELIMINARY CONSIDERATIONS The objective of this paper is to reshed some light on the broad subject of cleaning from the viewpoint of a museum conservator. With the rapid developments in new clean- ing techniques and analytical techniques in the last decade, it is important and necessary for the conservation community to constantly remind itself of the debate surrounding cleaning. In modern times, this debate began with the National Gallery of London “clean- ing controversy” of 1947. Then, as now, it would be good for someone who spends much time looking at a few square centimeters of a painting through a microscope to go to the window and look out into the distance. Although the dedication to detail is understand- able, one should not forget to look at the whole picture. The success of an intervention, in particular, that of cleaning a work of art, depends on the cooperation between practitioners, art historians, and scientists, a partnership that is not always free of confict. Relationships, historical facts, and questions of meaning must be collected and taken into account. A painting can be unbelievably deterministic, fascinating, and powerful, analogous to and perhaps even more so than literature or music. On the other hand, the physical Considerations of the Cleaning of Paintings Konrad Laudenbacher Konrad Laudenbacher, Würth Museum, Kün- zelsau, Baden Württemberg, Germany. Corre- spondence: k.laudenbacher@gmx.de. Manuscript received 19 November 2010; accepted 24 August 2012.