A restoration operation is selected based on the knowledge allowing to set its scope and choice, and also, on the necessity that links the operation to others and, thus, contributes to a series of ensuing contributions for protecting the work. An accurate conservation of the work must serve as ample, well-reasoned subject-matter for planning the restoration operation that envisages a connection, never too technical, between practices and science, knowledge and planning.

Care is the primary guarantee for each project; interventions should consist of serious, meticulous conservation, rather than radical restoration.