This contribution examines the seminal article titled The Idea of Patina and the Cleaning of Paintings, in which Paul Philippot both defined patina as a series of alterations affecting the work of art over time that produce irreversible, physicochemical changes, and, in turn, argued that cleaning, in any case, should not seek to restore the original state of the work of art, but rather to recognize this patina as evidence of its historical authenticity. After reviewing the text´s background and its context of production, this paper discusses the concept of patina and its implications in the restoration process in order to conclude that the cleaning limits depend on a critical analysis: while science offers objective information about an artwork and its state of conservation, the restorer must interpret it at the time of the object´s intervention, a process that cannot be fully objective since it greatly depends on the technical skill and experience of the specialist in charge of conservation-restoration decision-making.